1
|
LeBlanc ARH, Morrell AP, Sirovica S, Al-Jawad M, Labonte D, D'Amore DC, Clemente C, Wang S, Giuliani F, McGilvery CM, Pittman M, Kaye TG, Stevenson C, Capon J, Tapley B, Spiro S, Addison O. Iron-coated Komodo dragon teeth and the complex dental enamel of carnivorous reptiles. Nat Ecol Evol 2024:10.1038/s41559-024-02477-7. [PMID: 39048730 DOI: 10.1038/s41559-024-02477-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 05/08/2024] [Indexed: 07/27/2024]
Abstract
Komodo dragons (Varanus komodoensis) are the largest extant predatory lizards and their ziphodont (serrated, curved and blade-shaped) teeth make them valuable analogues for studying tooth structure, function and comparing with extinct ziphodont taxa, such as theropod dinosaurs. Like other ziphodont reptiles, V. komodoensis teeth possess only a thin coating of enamel that is nevertheless able to cope with the demands of their puncture-pull feeding. Using advanced chemical and structural imaging, we reveal that V. komodoensis teeth possess a unique adaptation for maintaining their cutting edges: orange, iron-enriched coatings on their tooth serrations and tips. Comparisons with other extant varanids and crocodylians revealed that iron sequestration is probably widespread in reptile enamels but it is most striking in V. komodoensis and closely related ziphodont species, suggesting a crucial role in supporting serrated teeth. Unfortunately, fossilization confounds our ability to consistently detect similar iron coatings in fossil teeth, including those of ziphodont dinosaurs. However, unlike V. komodoensis, some theropods possessed specialized enamel along their tooth serrations, resembling the wavy enamel found in herbivorous hadrosaurid dinosaurs. These discoveries illustrate unexpected and disparate specializations for maintaining ziphodont teeth in predatory reptiles.
Collapse
Affiliation(s)
- Aaron R H LeBlanc
- Centre for Oral, Clinical & Translational Sciences, King's College London, London, UK.
| | - Alexander P Morrell
- Centre for Oral, Clinical & Translational Sciences, King's College London, London, UK
| | - Slobodan Sirovica
- Centre for Oral, Clinical & Translational Sciences, King's College London, London, UK
- Centre for Oral Bioengineering, Queen Mary University of London, London, UK
| | | | - David Labonte
- Evolutionary Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, UK
| | | | - Christofer Clemente
- School of Science Engineering and Technology, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Siyang Wang
- Department of Materials, Imperial College London, London, UK
| | - Finn Giuliani
- Department of Materials, Imperial College London, London, UK
| | | | - Michael Pittman
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Thomas G Kaye
- Foundation for Scientific Advancement, Sierra Vista, AZ, USA
| | | | - Joe Capon
- Zoological Society of London, Regent's Park, London, UK
| | | | - Simon Spiro
- Wildlife Health Services, Zoological Society of London, Regent's Park, London, UK
| | - Owen Addison
- Centre for Oral, Clinical & Translational Sciences, King's College London, London, UK
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
2
|
Tomańska A, Stawinoga M, Szturo K, Styczyńska M, Klećkowska-Nawrot J, Janeczek M, Goździewska-Harłajczuk K, Melnyk O, Gębarowski T. Biological Significance of the Komodo Dragon's Tail ( Varanus komodoensis, Varanidae). Animals (Basel) 2024; 14:2142. [PMID: 39123668 PMCID: PMC11311070 DOI: 10.3390/ani14152142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 07/14/2024] [Accepted: 07/16/2024] [Indexed: 08/12/2024] Open
Abstract
The Komodo dragon is a unique reptile with an elongated tail that exhibits hitherto unknown adaptations and functions. This tail, composed of 60-86 vertebrae, serves diverse ecological and physiological roles. In juveniles, it is essential for an arboreal lifestyle and balance, while in adults, it functions as a tool for defense and offensive actions. It possesses characteristic haemal arches and a dorsal keel, along with well-developed muscles which enable precise tail control, influencing the Komodo dragon's maneuverability and directional changes. The tail stores adipose tissue, providing Komodo dragons with the ability to regulate body temperature and independence from other seasonal variations. The tail adipose tissue impacts numerous biochemical processes and may play a crucial role in the animals' metabolic strategies and reproductive capabilities. Its functions include providing essential mineral compounds for the organism, such as calcium, phosphorus, magnesium, iron, and zinc. Analysing the biochemical composition of tail fat is crucial for understanding the health of Komodo dragons.
Collapse
Affiliation(s)
- Anna Tomańska
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| | - Martyna Stawinoga
- Veterinary Biotechnology Student Science Club “Refectio”, Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| | - Kacper Szturo
- Veterinary Biotechnology Student Science Club “Refectio”, Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| | - Marzena Styczyńska
- Department of Human Nutrition, Faculty of Biotechnology and Food Science, Wroclaw University of Environmental and Life Sciences, Chełmońskiego St. 37/41, 51-630 Wroclaw, Poland
| | - Joanna Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| | - Maciej Janeczek
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| | - Oleksii Melnyk
- Department of Animal Anatomy, Histology and Pathomorphology, Faculty of Veterinary Medicine, National University of Life and Environmental Sciences of Ukraine, 03041 Kyiv, Ukraine
| | - Tomasz Gębarowski
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland
| |
Collapse
|
3
|
Gautam KB, Kumar A, Das A, Gupta SK. Himalayan upliftment and Shiwalik succession act as a cradle for divergence in Bengal monitor lizard Varanus bengalensis (Reptilia: Varanidae) in India. Cladistics 2023; 39:382-397. [PMID: 37200006 DOI: 10.1111/cla.12542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/01/2023] [Accepted: 04/05/2023] [Indexed: 05/19/2023] Open
Abstract
The Himalayan foothills and associated environment are well-known for driving the rapid diversification of many species and the formation of biodiversity hotspots. The effects of environmental change since the Miocene have accelerated species diversification, and hence are useful for studying population genetic structure, and evolutionary relationships via genetic approaches. To date, the effects of climatic fluctuations on the biogeography of large-bodied lizards have not been assessed comprehensively. Herein, we examine the diversification of Varanus bengalensis, focusing on its genetic structure to provide insights into how landscape structure and climatic fluctuations have shaped species differentiation. We confirm the existence of two distinct lineages within V. bengalensis distributed across the Himalayan foothills and the remainder of mainland India. Divergence analyses revealed the split between the Himalayan foothills and the remainder of the mainland lineages of V. bengalensis in the mid-Pliocene ~3.06 Ma, potentially as a consequence of the Siwalik broadening and climatic fluctuations across the Himalayan foothills. The results suggest recognition of a new lineage of V. bengalensis from the Himalayan foothills as a distinctive evolutionarily significant unit.
Collapse
Affiliation(s)
| | - Ajit Kumar
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand, 248001, India
| | - Abhijit Das
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand, 248001, India
| | - Sandeep Kumar Gupta
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand, 248001, India
| |
Collapse
|
4
|
Kępa M, Tomańska A, Staszewska J, Tarnowska M, Klećkowska-Nawrot J, Goździewska-Harłajczuk K, Kuźniarski A, Gębarowski T, Janeczek M. Functional Anatomy of the Thoracic Limb of the Komodo Dragon ( Varanus komodoensis). Animals (Basel) 2023; 13:2895. [PMID: 37760295 PMCID: PMC10525242 DOI: 10.3390/ani13182895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Since the Komodo dragon has been included on The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, it is crucial to know in detail its biology as there is a limited availability of research material on these animals-mainly those who died in zoos or whose remains were found in the wild. Anatomy is essential for understanding physiology, identification of diseases, adaptations in the environment, and behavior. In this dissection study, the relationship of individual anatomical structures was analyzed, the anatomy of the active and passive movement system of the thoracic limb was described, photographs were taken, and a radiographic examination was conducted. This species has its own differences, even within closely related lizard species. Varanus komodoensis possesses triceps muscles with three heads, and the wrist is extended with additional bones for greater flexibility of the hand. The muscles of the forelimb are analogous to the hind limb; however, they differ in the mass of individual muscles, especially those predisposed to perform the most important antigravity and locomotive functions.
Collapse
Affiliation(s)
- Michał Kępa
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| | - Anna Tomańska
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| | - Joanna Staszewska
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| | - Małgorzata Tarnowska
- Division of Histology and Embryology, Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Norwida St. 25, 50-375 Wrocław, Poland;
| | - Joanna Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| | - Amadeusz Kuźniarski
- Department of Prosthetic Dentistry, Faculty of Dentistry, Wrocław Medical University, Krakowska St. 26, 50-425 Wrocław, Poland;
| | - Tomasz Gębarowski
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| | - Maciej Janeczek
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska St. 1, 51-631 Wrocław, Poland; (M.K.); (J.S.); (J.K.-N.); (K.G.-H.); (M.J.)
| |
Collapse
|
5
|
Forth G. Surviving Dragons: Ethnographic Reports of Komodo Monitors (Varanus komodoensis) in Northeastern Flores. J ETHNOBIOL 2022. [DOI: 10.2993/0278-0771-42.4.417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Gregory Forth
- Professor Emeritus, Department of Anthropology, University of Alberta, Edmonton, Alberta, Canada T6G 2H4
| |
Collapse
|
6
|
Meijer HJM, Sutikna T, Wahyu Saptomo E, Tocheri MW. More bones of Leptoptilos robustus from Flores reveal new insights into giant marabou stork paleobiology and biogeography. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220435. [PMID: 35845853 PMCID: PMC9277297 DOI: 10.1098/rsos.220435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Liang Bua (Flores, Indonesia) has yielded remains of a faunal community that included small-bodied and small-brained hominins, dwarf proboscideans, Komodo dragons, vultures and giant marabou storks (Leptoptilos robustus). Previous research suggested that L. robustus evolved from a smaller L eptoptilos dubius-like Middle Pleistocene ancestor and may have been flightless. However, analyses of this species' considerably expanded hypodigm (n = 43, MNI = 5), which includes 21 newly discovered bones described here for the first time, reveals that the wing bones of L. robustus were well-developed and this species was almost certainly capable of active flight. Moreover, L. robustus bones are broadly similar to Leptoptilos falconeri remains from sites in Africa and Eurasia, and its overall size range is comparable to fossils attributed to L. falconeri and similar specimens, as well as those of Leptoptilos lüi (China) and Leptoptilos titan (Java). This suggests that a Pleistocene dispersal of L. falconeri into Island Southeast Asia may have given rise to populations of giant marabou storks in this region. As L. robustus and L. titan are the most recent known representatives of these once plentiful giant marabou storks, Island Southeast Asia likely acted as a refugium for the last surviving members of this lineage.
Collapse
Affiliation(s)
- Hanneke J. M. Meijer
- Department of Natural History, University Museum, University of Bergen, 5007 Bergen, Norway
- Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington DC 20013, USA
- Naturalis Biodiversity Center, Leiden, The Netherlands
| | - Thomas Sutikna
- Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - E. Wahyu Saptomo
- Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Pusat Penelitian Arkeologi Nasional, Jakarta 12510, Indonesia
| | - Matthew W. Tocheri
- Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington DC 20013, USA
- Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Department of Anthropology, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada
| |
Collapse
|
7
|
Iannucci A, Benazzo A, Natali C, Arida EA, Zein MSA, Jessop TS, Bertorelle G, Ciofi C. Population structure, genomic diversity and demographic history of Komodo dragons inferred from whole-genome sequencing. Mol Ecol 2021; 30:6309-6324. [PMID: 34390519 PMCID: PMC9292392 DOI: 10.1111/mec.16121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 07/28/2021] [Accepted: 08/03/2021] [Indexed: 02/07/2023]
Abstract
Population and conservation genetics studies have greatly benefited from the development of new techniques and bioinformatic tools associated with next-generation sequencing. Analysis of extensive data sets from whole-genome sequencing of even a few individuals allows the detection of patterns of fine-scale population structure and detailed reconstruction of demographic dynamics through time. In this study, we investigated the population structure, genomic diversity and demographic history of the Komodo dragon (Varanus komodoensis), the world's largest lizard, by sequencing the whole genomes of 24 individuals from the five main Indonesian islands comprising the entire range of the species. Three main genomic groups were observed. The populations of the Island of Komodo and the northern coast of Flores, in particular, were identified as two distinct conservation units. Degrees of genomic divergence among island populations were interpreted as a result of changes in sea level affecting connectivity across islands. Demographic inference suggested that Komodo dragons probably experienced a relatively steep population decline over the last million years, reaching a relatively stable Ne during the Saalian glacial cycle (400-150 thousand years ago) followed by a rapid Ne decrease. Genomic diversity of Komodo dragons was similar to that found in endangered or already extinct reptile species. Overall, this study provides an example of how whole-genome analysis of a few individuals per population can help define population structure and intraspecific demographic dynamics. This is particularly important when applying population genomics data to conservation of rare or elusive endangered species.
Collapse
Affiliation(s)
| | - Andrea Benazzo
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Chiara Natali
- Department of BiologyUniversity of FlorenceFirenzeItaly
| | - Evy Ayu Arida
- Research Center for BiologyThe Indonesian Institute of Sciences (LIPI)Cibinong Science CenterCibinongIndonesia
| | - Moch Samsul Arifin Zein
- Research Center for BiologyThe Indonesian Institute of Sciences (LIPI)Cibinong Science CenterCibinongIndonesia
| | - Tim S. Jessop
- School of Life and Environmental SciencesDeakin UniversityGeelongVic.Australia
| | - Giorgio Bertorelle
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Claudio Ciofi
- Department of BiologyUniversity of FlorenceFirenzeItaly
| |
Collapse
|
8
|
Carnosaurs as Apex Scavengers: Agent-based simulations reveal possible vulture analogues in late Jurassic Dinosaurs. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
9
|
Pavón-Vázquez CJ, Brennan IG, Keogh JS. A Comprehensive Approach to Detect Hybridization Sheds Light on the Evolution of Earth's Largest Lizards. Syst Biol 2021; 70:877-890. [PMID: 33512509 DOI: 10.1093/sysbio/syaa102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 11/14/2022] Open
Abstract
Hybridization between species occurs more frequently in vertebrates than traditionally thought but distinguishing ancient hybridization from other phenomena that generate similar evolutionary patterns remains challenging. Here, we used a comprehensive workflow to discover evidence of ancient hybridization between the Komodo dragon (Varanus komodoensis) from Indonesia and a common ancestor of an Australian group of monitor lizards known colloquially as sand monitors. Our data comprises >300 nuclear loci, mitochondrial genomes, phenotypic data, fossil and contemporary records, and past/present climatic data. We show that the four sand monitor species share more nuclear alleles with V. komodoensis than expected given a bifurcating phylogeny, likely as a result of hybridization between the latter species and a common ancestor of sand monitors. Sand monitors display phenotypes that are intermediate between their closest relatives and V. komodoensis. Biogeographic analyses suggest that V. komodoensis and ancestral sand monitors co-occurred in northern Australia. In agreement with the fossil record, this provides further evidence that the Komodo dragon once inhabited the Australian continent. Our study shows how different sources of evidence can be used to thoroughly characterize evolutionary histories that deviate from a treelike pattern, that hybridization can have long-lasting effects on phenotypes and that detecting hybridization can improve our understanding of evolutionary and biogeographic patterns.
Collapse
Affiliation(s)
- Carlos J Pavón-Vázquez
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Ian G Brennan
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - J Scott Keogh
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| |
Collapse
|
10
|
Georgalis GL, Abdel Gawad MK, Hassan SM, El-Barkooky AN, Hamdan MA. Oldest co-occurrence of Varanus and Python from Africa-first record of squamates from the early Miocene of Moghra Formation, Western Desert, Egypt. PeerJ 2020; 8:e9092. [PMID: 32509449 PMCID: PMC7255343 DOI: 10.7717/peerj.9092] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/09/2020] [Indexed: 11/20/2022] Open
Abstract
Lizard and snake remains from the early Miocene (Burdigalian) of the Moghra Formation, Egypt, are described herein. This material comprises the first fossil remains of squamates recovered from the otherwise rich and well known vertebrate assemblage of Moghra. The material pertains to two different genera, the varanid lizard Varanus and the pythonid snake Python and adds to the so far rather poorly known squamate fossil record from Africa. On the basis of the new remains, Moghra marks the oldest so far described co-occurrence of Varanus and Python in the African continent. The close sympatry of these two genera in the African fossil record is thoroughly analyzed and discussed, a co-existence, which is still widespread in the extant herpetofauna of the continent. Situated rather close to the so called "Levantine Corridor" and dated at the Burdigalian, practically when Afro-Arabia collided with Eurasia, the Moghra squamate assemblage offers the potential of important insights in the biogeography and dispersal events of vertebrate groups during the early Miocene.
Collapse
Affiliation(s)
| | | | - Safiya M. Hassan
- Geology Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | | | - Mohamed A. Hamdan
- Geology Department, Faculty of Science, Cairo University, Giza, Egypt
| |
Collapse
|
11
|
Hocknull SA, Lewis R, Arnold LJ, Pietsch T, Joannes-Boyau R, Price GJ, Moss P, Wood R, Dosseto A, Louys J, Olley J, Lawrence RA. Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration. Nat Commun 2020; 11:2250. [PMID: 32418985 PMCID: PMC7231803 DOI: 10.1038/s41467-020-15785-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 03/27/2020] [Indexed: 11/24/2022] Open
Abstract
Explanations for the Upper Pleistocene extinction of megafauna from Sahul (Australia and New Guinea) remain unresolved. Extinction hypotheses have advanced climate or human-driven scenarios, in spite of over three quarters of Sahul lacking reliable biogeographic or chronologic data. Here we present new megafauna from north-eastern Australia that suffered extinction sometime after 40,100 (±1700) years ago. Megafauna fossils preserved alongside leaves, seeds, pollen and insects, indicate a sclerophyllous forest with heathy understorey that was home to aquatic and terrestrial carnivorous reptiles and megaherbivores, including the world’s largest kangaroo. Megafauna species diversity is greater compared to southern sites of similar age, which is contrary to expectations if extinctions followed proposed migration routes for people across Sahul. Our results do not support rapid or synchronous human-mediated continental-wide extinction, or the proposed timing of peak extinction events. Instead, megafauna extinctions coincide with regionally staggered spatio-temporal deterioration in hydroclimate coupled with sustained environmental change. The causes of the Upper Pleistocene megafauna extinction in Australia and New Guinea are debated, but fossil data are lacking for much of this region. Here, Hocknull and colleagues report a new, diverse megafauna assemblage from north-eastern Australia that persisted until ~40,000 years ago.
Collapse
Affiliation(s)
- Scott A Hocknull
- Geosciences, Queensland Museum, 122 Gerler Rd., Hendra, QLD, 4011, Australia. .,School of BioSciences, Faculty of Science, University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Richard Lewis
- School of Physical Sciences, Environment Institute, and Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, North Terrace Campus, Adelaide, SA, 5005, Australia
| | - Lee J Arnold
- School of Physical Sciences, Environment Institute, and Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, North Terrace Campus, Adelaide, SA, 5005, Australia
| | - Tim Pietsch
- Australian Rivers Institute, Griffith University, Brisbane, QLD, 4122, Australia
| | - Renaud Joannes-Boyau
- Geoarchaeology and Archaeometry Research Group, Southern Cross GeoScience, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Gilbert J Price
- School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Patrick Moss
- School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Rachel Wood
- Radiocarbon Facility, Research School of Earth Sciences, Australian National University, Building 142 Mills Road, Canberra, ACT, 2601, Australia.,School of Archaeology and Anthropology, Australian National University, Building 44, Daley Road, Canberra, ACT, 2601, Australia
| | - Anthony Dosseto
- Wollongong Isotope Geochronology Laboratory, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Julien Louys
- Australian Research Centre for Human Evolution, Environmental Futures Research Institute, Griffith University, Mount Gravatt, QLD, 4122, Australia
| | - Jon Olley
- Australian Rivers Institute, Griffith University, Brisbane, QLD, 4122, Australia
| | - Rochelle A Lawrence
- Geosciences, Queensland Museum, 122 Gerler Rd., Hendra, QLD, 4011, Australia
| |
Collapse
|
12
|
Head JJ, Müller J. Squamate reptiles from Kanapoi: Faunal evidence for hominin paleoenvironments. J Hum Evol 2020; 140:102451. [DOI: 10.1016/j.jhevol.2018.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 01/18/2018] [Accepted: 01/23/2018] [Indexed: 11/16/2022]
|
13
|
Vasilyan D, Bukhsianidze M. The fossil record of the genus Varanus from the Southern Caucasus (Armenia, Georgia). PeerJ 2020; 8:e8322. [PMID: 31915588 PMCID: PMC6942675 DOI: 10.7717/peerj.8322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/30/2019] [Indexed: 11/20/2022] Open
Abstract
The Southern Caucasus, with its special geographic position and complex topography, is a well-known biodiversity hotspot. However, the formation of this hotspot remains largely unstudied. To reveal this, a thorough study of the fossil record of the region is necessary. In the present paper, we describe for the first time fossil monitor lizards (Varanus sp.) from two late Miocene localities from the Southern Caucasus (Jradzor, Armenia and Tetri Udabno, Georgia). We suggest that both fossils belong to a small-sized monitor lizard, comparable to the present-day species found in Iran and the Middle East (e.g., Iraq, Saudi Arabian)-the most western part of the extant monitor lizards' Eurasian distribution range. Our finds show that the genus had a broad distribution in the Eastern Paratethyan region during the late Miocene. In addition, we provide the probable temperature ranges for fossil localities.
Collapse
Affiliation(s)
- Davit Vasilyan
- JURASSICA Museum, Porrentruy, Switzerland
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | | |
Collapse
|
14
|
Porter WR, Witmer LM. Vascular Patterns in the Heads of Dinosaurs: Evidence for Blood Vessels, Sites of Thermal Exchange, and Their Role in Physiological Thermoregulatory Strategies. Anat Rec (Hoboken) 2019; 303:1075-1103. [DOI: 10.1002/ar.24234] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 03/22/2019] [Accepted: 05/11/2019] [Indexed: 11/11/2022]
Affiliation(s)
- William Ruger Porter
- Department of Biomedical Sciences Ohio University Heritage College of Osteopathic Medicine, Ohio Center for Ecology and Evolutionary Studies Athens Ohio
| | - Lawrence M. Witmer
- Department of Biomedical Sciences Ohio University Heritage College of Osteopathic Medicine, Ohio Center for Ecology and Evolutionary Studies Athens Ohio
| |
Collapse
|
15
|
van Hoek ML, Prickett MD, Settlage RE, Kang L, Michalak P, Vliet KA, Bishop BM. The Komodo dragon (Varanus komodoensis) genome and identification of innate immunity genes and clusters. BMC Genomics 2019; 20:684. [PMID: 31470795 PMCID: PMC6716921 DOI: 10.1186/s12864-019-6029-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 08/12/2019] [Indexed: 12/23/2022] Open
Abstract
Background We report the sequencing, assembly and analysis of the genome of the Komodo dragon (Varanus komodoensis), the largest extant lizard, with a focus on antimicrobial host-defense peptides. The Komodo dragon diet includes carrion, and a complex milieu of bacteria, including potentially pathogenic strains, has been detected in the saliva of wild dragons. They appear to be unaffected, suggesting that dragons have robust defenses against infection. While little information is available regarding the molecular biology of reptile immunity, it is believed that innate immunity, which employs antimicrobial host-defense peptides including defensins and cathelicidins, plays a more prominent role in reptile immunity than it does in mammals. . Results High molecular weight genomic DNA was extracted from Komodo dragon blood cells. Subsequent sequencing and assembly of the genome from the collected DNA yielded a genome size of 1.6 Gb with 45x coverage, and the identification of 17,213 predicted genes. Through further analyses of the genome, we identified genes and gene-clusters corresponding to antimicrobial host-defense peptide genes. Multiple β-defensin-related gene clusters were identified, as well as a cluster of potential Komodo dragon ovodefensin genes located in close proximity to a cluster of Komodo dragon β-defensin genes. In addition to these defensins, multiple cathelicidin-like genes were also identified in the genome. Overall, 66 β-defensin genes, six ovodefensin genes and three cathelicidin genes were identified in the Komodo dragon genome. Conclusions Genes with important roles in host-defense and innate immunity were identified in this newly sequenced Komodo dragon genome, suggesting that these organisms have a robust innate immune system. Specifically, multiple Komodo antimicrobial peptide genes were identified. Importantly, many of the antimicrobial peptide genes were found in gene clusters. We found that these innate immunity genes are conserved among reptiles, and the organization is similar to that seen in other avian and reptilian species. Having the genome of this important squamate will allow researchers to learn more about reptilian gene families and will be a valuable resource for researchers studying the evolution and biology of the endangered Komodo dragon. Electronic supplementary material The online version of this article (10.1186/s12864-019-6029-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Monique L van Hoek
- School of Systems Biology, George Mason University, Manassas, VA, 20110, USA
| | - M Dennis Prickett
- Dipartimento di Scienze della Vita-Edif. C11, Università di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy
| | - Robert E Settlage
- Advanced Research Computing, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Lin Kang
- Edward Via College of Osteopathic Medicine, Blacksburg, VA, 24060, USA
| | - Pawel Michalak
- Edward Via College of Osteopathic Medicine, Blacksburg, VA, 24060, USA.,Center for One Health Research, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, 24060, USA.,Institute of Evolution, University of Haifa, 3498838, Haifa, Israel
| | - Kent A Vliet
- Department of Biology, University of Florida, Gainesville, Florida, FL, 32611, USA
| | - Barney M Bishop
- Department of Chemistry, George Mason University, Manassas, VA, 20110, USA.
| |
Collapse
|
16
|
Temporal shifts in the distribution of murine rodent body size classes at Liang Bua (Flores, Indonesia) reveal new insights into the paleoecology of Homo floresiensis and associated fauna. J Hum Evol 2019; 130:45-60. [PMID: 31010543 DOI: 10.1016/j.jhevol.2019.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 02/14/2019] [Accepted: 02/14/2019] [Indexed: 11/20/2022]
Abstract
Liang Bua, the type locality of Homo floresiensis, is a limestone cave located in the western part of the Indonesian island of Flores. The relatively continuous stratigraphic sequence of the site spans the past ∼190 kyr and contains ∼275,000 taxonomically identifiable vertebrate skeletal elements, ∼80% of which belong to murine rodent taxa (i.e., rats). Six described genera are present at Liang Bua (Papagomys, Spelaeomys, Hooijeromys, Komodomys, Paulamys, and Rattus), one of which, Hooijeromys, is newly recorded in the site deposits, being previously known only from Early to Middle Pleistocene sites in central Flores. Measurements of the proximal femur (n = 10,212) and distal humerus (n = 1186) indicate five murine body size classes ranging from small (mouse-sized) to giant (common rabbit-sized) are present. The proportions of these five classes across successive stratigraphic units reveal two major changes in murine body size distribution due to significant shifts in the abundances of more open habitat-adapted medium-sized murines versus more closed habitat-adapted smaller-sized ones. One of these changes suggests a modest increase in available open habitats occurred ∼3 ka, likely the result of anthropogenic changes to the landscape related to farming by modern human populations. The other and more significant change occurred ∼60 ka suggesting a rapid shift from more open habitats to more closed conditions at this time. The abrupt reduction of medium-sized murines, along with the disappearance of H. floresiensis, Stegodon florensis insularis (an extinct proboscidean), Varanus komodoensis (Komodo dragon), Leptoptilos robustus (giant marabou stork), and Trigonoceps sp. (vulture) at Liang Bua ∼60-50 ka, is likely the consequence of these animals preferring and tracking more open habitats to elsewhere on the island. If correct, then the precise timing and nature of the extinction of H. floresiensis and its contemporaries must await new discoveries at Liang Bua or other as yet unexcavated sites on Flores.
Collapse
|
17
|
Shine R, Somaweera R. Last lizard standing: The enigmatic persistence of the Komodo dragon. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
18
|
The spatio-temporal distribution of archaeological and faunal finds at Liang Bua (Flores, Indonesia) in light of the revised chronology for Homo floresiensis. J Hum Evol 2018; 124:52-74. [PMID: 30173885 DOI: 10.1016/j.jhevol.2018.07.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 06/27/2018] [Accepted: 07/04/2018] [Indexed: 11/22/2022]
Abstract
Liang Bua, the type site of Homo floresiensis, is a limestone cave on the Indonesian island of Flores with sedimentary deposits currently known to range in age from about 190 thousand years (ka) ago to the present. Recent revision of the stratigraphy and chronology of this depositional sequence suggests that skeletal remains of H. floresiensis are between ∼100 and 60 ka old, while cultural evidence of this taxon occurs until ∼50 ka ago. Here we examine the compositions of the faunal communities and stone artifacts, by broad taxonomic groups and raw materials, throughout the ∼190 ka time interval preserved in the sequence. Major shifts are observed in both the faunal and stone artifact assemblages that reflect marked changes in paleoecology and hominin behavior, respectively. Our results suggest that H. floresiensis and Stegodon florensis insularis, along with giant marabou stork (Leptoptilos robustus) and vulture (Trigonoceps sp.), were likely extinct by ∼50 ka ago. Moreover, an abrupt and statistically significant shift in raw material preference due to an increased use of chert occurs ∼46 thousand calibrated radiocarbon (14C) years before present (ka cal. BP), a pattern that continues through the subsequent stratigraphic sequence. If an increased preference for chert does, in fact, characterize Homo sapiens assemblages at Liang Bua, as previous studies have suggested (e.g., Moore et al., 2009), then the shift observed here suggests that modern humans arrived on Flores by ∼46 ka cal. BP, which would be the earliest cultural evidence of modern humans in Indonesia.
Collapse
|
19
|
Turvey ST, Crees JJ, Hansford J, Jeffree TE, Crumpton N, Kurniawan I, Setiyabudi E, Guillerme T, Paranggarimu U, Dosseto A, van den Bergh GD. Quaternary vertebrate faunas from Sumba, Indonesia: implications for Wallacean biogeography and evolution. Proc Biol Sci 2018; 284:rspb.2017.1278. [PMID: 28855367 PMCID: PMC5577490 DOI: 10.1098/rspb.2017.1278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/21/2017] [Indexed: 12/03/2022] Open
Abstract
Historical patterns of diversity, biogeography and faunal turnover remain poorly understood for Wallacea, the biologically and geologically complex island region between the Asian and Australian continental shelves. A distinctive Quaternary vertebrate fauna containing the small-bodied hominin Homo floresiensis, pygmy Stegodon proboscideans, varanids and giant murids has been described from Flores, but Quaternary faunas are poorly known from most other Lesser Sunda Islands. We report the discovery of extensive new fossil vertebrate collections from Pleistocene and Holocene deposits on Sumba, a large Wallacean island situated less than 50 km south of Flores. A fossil assemblage recovered from a Pleistocene deposit at Lewapaku in the interior highlands of Sumba, which may be close to 1 million years old, contains a series of skeletal elements of a very small Stegodon referable to S. sumbaensis, a tooth attributable to Varanus komodoensis, and fragmentary remains of unidentified giant murids. Holocene cave deposits at Mahaniwa dated to approximately 2000–3500 BP yielded extensive material of two new genera of endemic large-bodied murids, as well as fossils of an extinct frugivorous varanid. This new baseline for reconstructing Wallacean faunal histories reveals that Sumba's Quaternary vertebrate fauna, although phylogenetically distinctive, was comparable in diversity and composition to the Quaternary fauna of Flores, suggesting that similar assemblages may have characterized Quaternary terrestrial ecosystems on many or all of the larger Lesser Sunda Islands.
Collapse
Affiliation(s)
- Samuel T Turvey
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Jennifer J Crees
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - James Hansford
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK.,Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
| | - Timothy E Jeffree
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Nick Crumpton
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | | | | | - Thomas Guillerme
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot SL5 7PY, UK
| | | | - Anthony Dosseto
- Wollongong Isotope Geochronology Laboratory, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Gerrit D van den Bergh
- Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| |
Collapse
|
20
|
|
21
|
Leppard TP. The Biophysical Effects of Neolithic Island Colonization: General Dynamics and Sociocultural Implications. HUMAN ECOLOGY: AN INTERDISCIPLINARY JOURNAL 2017; 45:555-568. [PMID: 29170588 PMCID: PMC5680384 DOI: 10.1007/s10745-017-9939-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Does anthropogenic environmental change constrain long-term sociopolitical outcomes? It is clear that human colonization of islands radically alters their biological and physical systems. Despite considerable contextual variability in local specificities of this alteration, I argue that these processes are to some extent regular, predictable, and have socio-political implications. Reviewing the data for post-colonization ecodynamics, I show that Neolithic colonization of previously insulated habitats drives biotic homogenization. I argue that we should expect such homogenization to promote regular types of change in biophysical systems, types of change that can be described in sum as environmentally convergent. Such convergence should have significant implications for human social organization over the long term, and general dynamics of this sort are relevant in the context of understanding remarkably similar social evolutionary trajectories towards wealth-inequality not only islands, but also more generally.
Collapse
Affiliation(s)
- Thomas P. Leppard
- McDonald Institute for Archaeological Research, University of Cambridge, Downing Street, Cambridge, CB2 3ER UK
| |
Collapse
|
22
|
Meijer HJM, Awe Due R, Sutikna T, Saptomo W, Jatmiko, Wasisto S, Tocheri MW, Mayr G. Late Pleistocene songbirds of Liang Bua (Flores, Indonesia); the first fossil passerine fauna described from Wallacea. PeerJ 2017; 5:e3676. [PMID: 28828271 PMCID: PMC5563437 DOI: 10.7717/peerj.3676] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 07/20/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Passerines (Aves: Passeriformes) dominate modern terrestrial bird communities yet their fossil record is limited. Liang Bua is a large cave on the Indonesian island of Flores that preserves Late Pleistocene-Holocene deposits (∼190 ka to present day). Birds are the most diverse faunal group at Liang Bua and are present throughout the stratigraphic sequence. METHODS We examined avian remains from the Late Pleistocene deposits of Sector XII, a 2 × 2 m area excavated to about 8.5 m depth. Although postcranial passerine remains are typically challenging to identify, we found several humeral characters particularly useful in discriminating between groups, and identified 89 skeletal elements of passerines. RESULTS At least eight species from eight families are represented, including the Large-billed Crow (Corvus cf. macrorhynchos), the Australasian Bushlark (Mirafra javanica), a friarbird (Philemon sp.), and the Pechora Pipit (Anthus cf. gustavi). DISCUSSION These remains constitute the first sample of fossil passerines described in Wallacea. Two of the taxa no longer occur on Flores today; a large sturnid (cf. Acridotheres) and a grassbird (Megalurus sp.). Palaeoecologically, the songbird assemblage suggests open grassland and tall forests, which is consistent with conditions inferred from the non-passerine fauna at the site. Corvus cf. macrorhynchos, found in the Homo floresiensis-bearing layers, was likely part of a scavenging guild that fed on carcasses of Stegodon florensis insularis alongside vultures (Trigonoceps sp.), giant storks (Leptoptilos robustus), komodo dragons (Varanus komodoensis), and probably H. floresiensis as well.
Collapse
Affiliation(s)
- Hanneke J M Meijer
- University Museum of Bergen, Department of Natural History, University of Bergen, Bergen, Norway.,Human Origins Program, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
| | - Rokus Awe Due
- Pusat Penelitian Arkeologi Nasional, Jakarta, Indonesia
| | - Thomas Sutikna
- Pusat Penelitian Arkeologi Nasional, Jakarta, Indonesia.,Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Wahyu Saptomo
- Pusat Penelitian Arkeologi Nasional, Jakarta, Indonesia
| | - Jatmiko
- Pusat Penelitian Arkeologi Nasional, Jakarta, Indonesia
| | - Sri Wasisto
- Pusat Penelitian Arkeologi Nasional, Jakarta, Indonesia
| | - Matthew W Tocheri
- Human Origins Program, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America.,Department of Anthropology, Lakehead University, Thunder Bay, Canada
| | - Gerald Mayr
- Ornithological Section, Senckenberg Research Institute, Frankfurt am Main, Germany
| |
Collapse
|
23
|
Koludarov I, Jackson TN, Brouw BOD, Dobson J, Dashevsky D, Arbuckle K, Clemente CJ, Stockdale EJ, Cochran C, Debono J, Stephens C, Panagides N, Li B, Manchadi MLR, Violette A, Fourmy R, Hendrikx I, Nouwens A, Clements J, Martelli P, Kwok HF, Fry BG. Enter the Dragon: The Dynamic and Multifunctional Evolution of Anguimorpha Lizard Venoms. Toxins (Basel) 2017; 9:E242. [PMID: 28783084 PMCID: PMC5577576 DOI: 10.3390/toxins9080242] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/04/2017] [Accepted: 08/04/2017] [Indexed: 01/08/2023] Open
Abstract
While snake venoms have been the subject of intense study, comparatively little work has been done on lizard venoms. In this study, we have examined the structural and functional diversification of anguimorph lizard venoms and associated toxins, and related these results to dentition and predatory ecology. Venom composition was shown to be highly variable across the 20 species of Heloderma, Lanthanotus, and Varanus included in our study. While kallikrein enzymes were ubiquitous, they were also a particularly multifunctional toxin type, with differential activities on enzyme substrates and also ability to degrade alpha or beta chains of fibrinogen that reflects structural variability. Examination of other toxin types also revealed similar variability in their presence and activity levels. The high level of venom chemistry variation in varanid lizards compared to that of helodermatid lizards suggests that venom may be subject to different selection pressures in these two families. These results not only contribute to our understanding of venom evolution but also reveal anguimorph lizard venoms to be rich sources of novel bioactive molecules with potential as drug design and development lead compounds.
Collapse
Affiliation(s)
- Ivan Koludarov
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Timothy Nw Jackson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
- Australian Venom Research Unit, School of Biomedical Sciences, Level 2 Medical Building, University of Melbourne, Victoria 3010, Australia.
| | - Bianca Op den Brouw
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - James Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Daniel Dashevsky
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Kevin Arbuckle
- Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK.
| | - Christofer J Clemente
- University of the Sunshine Coast, School of Science and Engineering, Sippy Downs, Queensland 4558, Australia.
| | | | - Chip Cochran
- Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Jordan Debono
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Carson Stephens
- School of Biomedical Sciences, Queensland University of Technology, Brisbane QLD 4001, Australia.
| | - Nadya Panagides
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Bin Li
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau.
| | | | - Aude Violette
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium.
| | - Rudy Fourmy
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium.
| | - Iwan Hendrikx
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| | - Amanda Nouwens
- School of Chemistry and Molecular Biology, University of Queenslnd, St. Lucia QLD 4072, Australia.
| | - Judith Clements
- School of Biomedical Sciences, Queensland University of Technology, Brisbane QLD 4001, Australia.
| | | | - Hang Fai Kwok
- Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau.
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia QLD 4072, Australia.
| |
Collapse
|
24
|
Long JA. Why Australasian vertebrate animals are so unique - A palaeontological perspective. Gen Comp Endocrinol 2017; 244:2-10. [PMID: 27269378 DOI: 10.1016/j.ygcen.2016.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 05/20/2016] [Accepted: 06/02/2016] [Indexed: 11/25/2022]
Abstract
Australasia has a unique fauna of living vertebrates, which include the oldest known species on the planet (the lungfish Neoceratodus) as well as many diverse, highly endemic families of fish, amphibians, reptiles, birds and mammals. The origin of most of the Australian vertebrate fauna has developed from two phases. Firstly, when Australia was subsumed within the greater Gondwana landmass, migration of animals from one region to another was possible by a land connection. Many of our most primitive forms of reptiles and mammals probably entered the country at this time, such as varanids, madtsooid snakes, monotremes and basal marsupials. Secondly, following the breakup of Gondwana, the isolation of Australia for its last 40 million years and subsequent changing climatic conditions drove the radiation of marsupial, reptile and amphibian families within the continent. The gradual aridification of central Australia further divided the landmass into discrete regional areas characterised by rainfall, vegetation, and climatic zones.
Collapse
Affiliation(s)
- John A Long
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia.
| |
Collapse
|
25
|
Suraprasit K, Jaeger JJ, Chaimanee Y, Chavasseau O, Yamee C, Tian P, Panha S. The Middle Pleistocene vertebrate fauna from Khok Sung (Nakhon Ratchasima, Thailand): biochronological and paleobiogeographical implications. Zookeys 2016:1-157. [PMID: 27667928 PMCID: PMC5027644 DOI: 10.3897/zookeys.613.8309] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/15/2016] [Indexed: 11/12/2022] Open
Abstract
The fluviatile terrace deposits of Khok Sung, Nakhon Ratchasima province, have yielded more than one thousand fossils, making this the richest Pleistocene vertebrate fauna of Thailand. The excellent preservation of the specimens allows precise characterization of the faunal composition. The mammalian fauna consists of fifteen species in thirteen genera, including a primate, a canid, a hyaenid, proboscideans, rhinoceroses, a suid, cervids, and bovids. Most species correspond to living taxa but globally (Stegodon cf. orientalis) and locally (Crocuta crocuta ultima, Rhinoceros unicornis, Sus barbatus, and Axis axis) extinct taxa were also present. The identification of Axis axis in Khok Sung, a chital currently restricted to the Indian Subcontinent, represents the first record of the species in Southeast Asia. Three reptilian taxa: Crocodylus cf. siamensis, Python sp., and Varanus sp., are also identified. Faunal correlations with other Southeast Asian sites suggest a late Middle to early Late Pleistocene age for the Khok Sung assemblage. However, the Khok Sung mammalian fauna is most similar to that of Thum Wiman Nakin, dated to older than 169 ka. The Khok Sung large mammal assemblage mostly comprises mainland Southeast Asian taxa that migrated to Java during the latest Middle Pleistocene, supporting the hypothesis that Thailand was a biogeographic pathway for the Sino-Malayan migration event from South China to Java.
Collapse
Affiliation(s)
- Kantapon Suraprasit
- Institut International de Paléoprimatologie et de Paléontologie Humaine: Evolution et Paléoenvironnements, UMR CNRS 7262, Université de Poitiers, 6 rue Michel Brunet, 86022 Poitiers, France; Biological Sciences Program, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jean-Jacques Jaeger
- Institut International de Paléoprimatologie et de Paléontologie Humaine: Evolution et Paléoenvironnements, UMR CNRS 7262, Université de Poitiers, 6 rue Michel Brunet, 86022 Poitiers, France
| | - Yaowalak Chaimanee
- Institut International de Paléoprimatologie et de Paléontologie Humaine: Evolution et Paléoenvironnements, UMR CNRS 7262, Université de Poitiers, 6 rue Michel Brunet, 86022 Poitiers, France
| | - Olivier Chavasseau
- Institut International de Paléoprimatologie et de Paléontologie Humaine: Evolution et Paléoenvironnements, UMR CNRS 7262, Université de Poitiers, 6 rue Michel Brunet, 86022 Poitiers, France
| | - Chotima Yamee
- Department of Mineral Resources, Rama VI Road, Bangkok, 10400, Thailand
| | - Pannipa Tian
- Department of Mineral Resources, Rama VI Road, Bangkok, 10400, Thailand
| | - Somsak Panha
- Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| |
Collapse
|
26
|
Johnson Pokorná M, Altmanová M, Rovatsos M, Velenský P, Vodička R, Rehák I, Kratochvíl L. First Description of the Karyotype and Sex Chromosomes in the Komodo Dragon (Varanus komodoensis). Cytogenet Genome Res 2016; 148:284-91. [DOI: 10.1159/000447340] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2016] [Indexed: 11/19/2022] Open
Abstract
The Komodo dragon (Varanus komodoensis) is the largest lizard in the world. Surprisingly, it has not yet been cytogenetically examined. Here, we present the very first description of its karyotype and sex chromosomes. The karyotype consists of 2n = 40 chromosomes, 16 macrochromosomes and 24 microchromosomes. Although the chromosome number is constant for all species of monitor lizards (family Varanidae) with the currently reported karyotype, variability in the morphology of the macrochromosomes has been previously documented within the group. We uncovered highly differentiated ZZ/ZW sex microchromosomes with a heterochromatic W chromosome in the Komodo dragon. Sex chromosomes have so far only been described in a few species of varanids including V. varius, the sister species to Komodo dragon, whose W chromosome is notably larger than that of the Komodo dragon. Accumulations of several microsatellite sequences in the W chromosome have recently been detected in 3 species of monitor lizards; however, these accumulations are absent from the W chromosome of the Komodo dragon. In conclusion, although varanids are rather conservative in karyotypes, their W chromosomes exhibit substantial variability at the sequence level, adding further evidence that degenerated sex chromosomes may represent the most dynamic genome part.
Collapse
|
27
|
Weijola V, Kraus F, Vahtera V, Lindqvist C, Donnellan SC. Reinstatement of Varanus douarrha Lesson, 1830 as a valid species with comments on the zoogeography of monitor lizards (Squamata : Varanidae) in the Bismarck Archipelago, Papua New Guinea. AUST J ZOOL 2016. [DOI: 10.1071/zo16038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The distribution and taxonomy of varanid lizards occurring in the Bismarck Archipelago is revised on the basis of field surveys, examination of museum vouchers and molecular phylogenetic analyses. A total of four species is recorded: Varanus indicus and Varanus finschi on New Britain and some of its offshore islands, Varanus douarrha on New Ireland, Lavongai and Djaul, and Varanus semotus on Mussau Island. V. douarrha, previously mistaken for both V. indicus and V. finschi, is shown to be the only species represented on New Ireland and is here resurrected as a valid taxon based on an integrated approach combining morphological and molecular evidence. Phylogenetic analyses of two mitochondrial genes suggest that V. indicus is a relatively recent immigrant to the Bismarck Islands, whereas V. douarrha, V. finschi and V. semotus have significantly longer histories in the island group. Together with the recently described V. semotus the revalidation of V. douarrha doubles the number of species known to occur in the Bismarck region and highlights an important component of both local and regional endemism.
Collapse
|
28
|
Delfino M, DE Vos J. A giant crocodile in the Dubois Collection from the Pleistocene of Kali Gedeh (Java). Integr Zool 2014; 9:141-147. [PMID: 24673759 DOI: 10.1111/1749-4877.12065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The fauna of the Pleistocene Homo-bearing sites of Java has been well known for more than a century. A recent revision of the crocodylian remains confirmed both the validity of Gavialis bengawanicus and the synonymization of Crocodylus ossifragus with C. siamensis. Here we report on a still unpublished crocodylian specimen collected by Eugene Dubois in the latest Early Pleistocene of Kali Gedeh that can be tentatively referred to the genus Crocodylus. The size of the specimen, the approximately 1 m long lower jaw in particular, indicated that this crocodile attained a total length of approximately 6 or 7 m. Along with specimens from the Plio-Pleistocene of Africa, this material provides evidence for gigantism in Crocodylus. It is not clear whether or not the 'temperature-size rule' applies to fossil crocodylians, but due to the growing interest in predicting future temperature-related size changes of the extant organisms, it would be interesting to study in detail the past reaction to temperature changes of crocodylians and other terrestrial ectothermic animals.
Collapse
Affiliation(s)
- Massimo Delfino
- Earth Sciences Department, University of Torino, Torino, Italy.,Catalan Institute of Palaeontology Miquel Crusafont, Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
| | - John DE Vos
- Naturalis Biodiversity Center, Leiden, Netherlands
| |
Collapse
|
29
|
Conrad JL, Balcarcel AM, Mehling CM. Earliest example of a giant monitor lizard (Varanus, Varanidae, Squamata). PLoS One 2012; 7:e41767. [PMID: 22900001 PMCID: PMC3416840 DOI: 10.1371/journal.pone.0041767] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Accepted: 06/27/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. METHODOLOGY/PRINCIPAL FINDINGS A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. CONCLUSIONS/SIGNIFICANCE The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors.
Collapse
Affiliation(s)
- Jack L Conrad
- Anatomy Department, New York College of Osteopathic Medicine, Old Westbury, New York, United States of America.
| | | | | |
Collapse
|
30
|
Fry BG, Casewell NR, Wüster W, Vidal N, Young B, Jackson TNW. The structural and functional diversification of the Toxicofera reptile venom system. Toxicon 2012; 60:434-48. [PMID: 22446061 DOI: 10.1016/j.toxicon.2012.02.013] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 02/23/2012] [Accepted: 02/28/2012] [Indexed: 11/25/2022]
Abstract
The evolutionary origin and diversification of the reptilian venom system is described. The resolution of higher-order molecular phylogenetics has clearly established that a venom system is ancestral to snakes. The diversification of the venom system within lizards is discussed, as is the role of venom delivery in the behavioural ecology of these taxa (particularly Varanus komodoensis). The more extensive diversification of the venom system in snakes is summarised, including its loss in some clades. Finally, we discuss the contentious issue of a definition for "venom", supporting an evolutionary definition that recognises the homology of both the venom delivery systems and the toxins themselves.
Collapse
Affiliation(s)
- Bryan G Fry
- Venom Evolution Research Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Queensland 4072, Australia.
| | | | | | | | | | | |
Collapse
|
31
|
Hawlitschek O, Hendrich L, Balke M. Molecular phylogeny of the squeak beetles, a family with disjunct Palearctic-Australian range. Mol Phylogenet Evol 2012; 62:550-4. [DOI: 10.1016/j.ympev.2011.09.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 09/12/2011] [Accepted: 09/23/2011] [Indexed: 11/25/2022]
|
32
|
D'Amore DC, Moreno K, McHenry CR, Wroe S. The effects of biting and pulling on the forces generated during feeding in the Komodo dragon (Varanus komodoensis). PLoS One 2011; 6:e26226. [PMID: 22028837 PMCID: PMC3197624 DOI: 10.1371/journal.pone.0026226] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 09/22/2011] [Indexed: 11/19/2022] Open
Abstract
In addition to biting, it has been speculated that the forces resulting from pulling on food items may also contribute to feeding success in carnivorous vertebrates. We present an in vivo analysis of both bite and pulling forces in Varanus komodoensis, the Komodo dragon, to determine how they contribute to feeding behavior. Observations of cranial modeling and behavior suggest that V. komodoensis feeds using bite force supplemented by pulling in the caudal/ventrocaudal direction. We tested these observations using force gauges/transducers to measure biting and pulling forces. Maximum bite force correlates with both body mass and total body length, likely due to increased muscle mass. Individuals showed consistent behaviors when biting, including the typical medial-caudal head rotation. Pull force correlates best with total body length, longer limbs and larger postcranial motions. None of these forces correlated well with head dimensions. When pulling, V. komodoensis use neck and limb movements that are associated with increased caudal and ventral oriented force. Measured bite force in Varanus komodoensis is similar to several previous estimations based on 3D models, but is low for its body mass relative to other vertebrates. Pull force, especially in the ventrocaudal direction, would allow individuals to hunt and deflesh with high success without the need of strong jaw adductors. In future studies, pull forces need to be considered for a complete understanding of vertebrate carnivore feeding dynamics.
Collapse
Affiliation(s)
- Domenic C D'Amore
- Graduate Program in Ecology and Evolution, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, United States of America.
| | | | | | | |
Collapse
|