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Ponstein J, MacDougall MJ, Fröbisch J. A comprehensive phylogeny and revised taxonomy of Diadectomorpha with a discussion on the origin of tetrapod herbivory. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231566. [PMID: 39036512 PMCID: PMC11257076 DOI: 10.1098/rsos.231566] [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: 11/13/2023] [Revised: 03/23/2024] [Accepted: 04/08/2024] [Indexed: 07/23/2024]
Abstract
Among terrestrial tetrapods, the origin of herbivory marked a key evolutionary event that allowed for the evolution of modern terrestrial ecosystems. A 100 Ma gap separates the oldest terrestrial tetrapods and the first undisputed herbivorous tetrapods. While four clades of early tetrapod herbivores are undisputed amniotes, the phylogenetic position of Diadectomorpha with respect to Amniota has long been controversial. Given that the origin of herbivory coincides with the oldest amniotes, and obligate herbivory is unknown within amphibians, this suggests that a key adaptation necessary to evolve obligate herbivory is unique to amniotes. Historically, phylogenetic analyses have found Diadectomorpha as the sister-group to amniotes, but recent analyses recover Diadectomorpha as sister-group to Synapsida, within Amniota. We tested whether diadectomorphs are amniotes by updating the most recent character-taxon matrix. Specifically, we added new characters from the lower jaw and added diadectomorph taxa, resulting in a dataset of 341 characters and 61 operational taxonomic units. We updated the description of five diadectomorph jaws using microcomputed tomography data. Our majority-rule consensus places Diadectomorpha as sister-group to Synapsida; other methods do not recover this relationship. We revise diadectomorph taxonomy, erecting a new species from the early Permian Bromacker locality, Germany, and a new genus to accommodate 'Diadectes' sanmiguelensis.
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Affiliation(s)
- Jasper Ponstein
- Humboldt-Universität zu Berlin, Unter den Linden 6, 10117 Berlin, Germany
- Museum für Naturkunde Berlin, Invalidenstraße 43, 10115 Berlin, Germany
- Oertijdmuseum, Bosscheweg 80, 5283 WB Boxtel, The Netherlands
| | | | - Jörg Fröbisch
- Humboldt-Universität zu Berlin, Unter den Linden 6, 10117 Berlin, Germany
- Museum für Naturkunde Berlin, Invalidenstraße 43, 10115 Berlin, Germany
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Carlisbino T, de Farias BDM, Sedor FA, Soares MB, Schultz CL. Replacement tooth in mesosaurs and new data on dental microanatomy and microstructure. Anat Rec (Hoboken) 2024. [PMID: 38581219 DOI: 10.1002/ar.25442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 04/08/2024]
Abstract
The Permian mesosaurs are well known for being the earliest amniotes to exhibit adaptations for living in a marine environment (Irati-Whitehill Sea). In addition to their set of skeletal features associated with aquatic dwelling life, their dentition includes important characteristics related to feeding in this habitat, which is described in this work, based on the analysis of mesosaur specimens from the Lower Permian Irati Formation of Brazil. Mesosaurs have several slender, conical teeth bordered by enamel apicobasal ridges, a feature predominantly found in aquatic amniotes. Internally, the dentine walls are formed by the arrangement of layers of orthodentine and globular dentine. To prevent tooth loss, the basal area is equipped with plicidentine, a particular type of orthodentine, allied with cementum, alveolar bone trabeculae, and periodontal space that reinforces anchorage and provides some flexibility. The teeth are replaced in a labio-vertical path, and the dentition replaces alternately. This feature is regarded as plesiomorphic, and it ensures the oral cavity is supplied with enough teeth. However, these features do not the assessment of whether mesosaurs teeth were capable of piercing prey with resistant tegument. Instead, we interpret this adaptation as a mechanism for catching prey, at least in adults, and we endorse a possible ontogenetic dietary shift from small to large forms.
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Affiliation(s)
- Thiago Carlisbino
- Programa de Pós-graduação em Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Fernando Antonio Sedor
- Museu de Ciências Naturais, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, Brazil
| | - Marina Bento Soares
- Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cesar Leandro Schultz
- Programa de Pós-graduação em Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Barboza M, Kallaway K. Gross and microanatomic description of the dental pads of the Florida manatee, Trichechus manatus latirostris, and their importance to mastication. Arch Oral Biol 2024; 158:105871. [PMID: 38128336 DOI: 10.1016/j.archoralbio.2023.105871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 12/01/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE Florida manatee feeding ecology is critical to species survival, but the role of dental pads in feeding has received limited attention. This study characterized the gross and microscopic anatomy of the manatee's dorsal and ventral dental pad in relation to these structures' importance in mastication, which furthers our understanding of manatee feeding and health. DESIGN Whole heads from 6 animals (4 male and 2 female) of varying sizes were examined grossly. Sections (5 µm) from throughout the dorsal and ventral dental pads were stained with Hematoxylin and Eosin to document microanatomy. The thickness of the epithelium and stratum corneum were measured. RESULTS The ventral dental pad epidermal (1129-3391 µm) and stratum corneum (331-1848 µm) thickness increased with increased body size. The dorsal dental pad epidermal (690-1988 µm) and stratum corneum (121-974 µm) thickness varied relative to size. The dental pad anatomy, including the thickened stratum corneum, indicates an importance similar to molars in grinding and physically breaking up plant material. Extensive appendages including filiform-like papillae and well-developed rete were observed and likely provide physical support for mastication. CONCLUSION While the sample size limits specific conclusions based on sex or age, it provides a good overview of the anatomy of the dental pads. The manatee is the only mammal known to have a ventral dental pad and the well-developed grinding surfaces demonstrates a crucial role in mastication for these structures. These dental pads should be evaluated during health checks and necropsies and considered in future research on manatee's feeding mechanisms.
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Affiliation(s)
- Meghan Barboza
- Southern Connecticut State University, 501 Crescent Street, New Haven, CT 06515, USA.
| | - Kiara Kallaway
- Atkins Engineering Consulting, 482 S Keller Rd, Orlando, FL 32810, USA.
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Brownstein CD, Meyer DL, Fabbri M, Bhullar BAS, Gauthier JA. Evolutionary origins of the prolonged extant squamate radiation. Nat Commun 2022; 13:7087. [PMID: 36446761 PMCID: PMC9708687 DOI: 10.1038/s41467-022-34217-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 10/18/2022] [Indexed: 11/30/2022] Open
Abstract
Squamata is the most diverse clade of terrestrial vertebrates. Although the origin of pan-squamates lies in the Triassic, the oldest undisputed members of extant clades known from nearly complete, uncrushed material come from the Cretaceous. Here, we describe three-dimensionally preserved partial skulls of two new crown lizards from the Late Jurassic of North America. Both species are placed at the base of the skink, girdled, and night lizard clade Pan-Scincoidea, which consistently occupies a position deep inside the squamate crown in both morphological and molecular phylogenies. The new lizards show that several features uniting pan-scincoids with another major lizard clade, the pan-lacertoids, in trees using morphology were convergently acquired as predicted by molecular analyses. Further, the palate of one new lizard bears a handful of ancestral saurian characteristics lost in nearly all extant squamates, revealing an underappreciated degree of complex morphological evolution in the early squamate crown. We find strong evidence for close relationships between the two new species and Cretaceous taxa from Eurasia. Together, these results suggest that early crown squamates had a wide geographic distribution and experienced complicated morphological evolution even while the Rhynchocephalia, now solely represented by the tuatara, was the dominant clade of lepidosaurs.
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Affiliation(s)
- Chase D. Brownstein
- grid.47100.320000000419368710Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT USA ,Stamford Museum and Nature Center, Stamford, CT USA
| | - Dalton L. Meyer
- grid.47100.320000000419368710Department of Earth and Planetary Sciences, Yale University, New Haven, CT USA
| | - Matteo Fabbri
- grid.47100.320000000419368710Department of Earth and Planetary Sciences, Yale University, New Haven, CT USA ,grid.299784.90000 0001 0476 8496Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, IL USA
| | - Bhart-Anjan S. Bhullar
- grid.47100.320000000419368710Department of Earth and Planetary Sciences, Yale University, New Haven, CT USA ,grid.47100.320000000419368710Yale Peabody Museum, Yale University, New Haven, CT USA
| | - Jacques A. Gauthier
- grid.47100.320000000419368710Department of Earth and Planetary Sciences, Yale University, New Haven, CT USA ,grid.47100.320000000419368710Yale Peabody Museum, Yale University, New Haven, CT USA
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Matsumoto R, Fujiwara S, Evans SE. Feeding behaviour and functional morphology of the neck in the long-snouted aquatic fossil reptile Champsosaurus (Reptilia: Diapsida) in comparison with the modern crocodilian Gavialis gangeticus. J Anat 2022; 240:893-913. [PMID: 34865223 PMCID: PMC9005684 DOI: 10.1111/joa.13600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 10/19/2022] Open
Abstract
The extinct freshwater choristoderan reptiles Champsosaurus and Simoedosaurus are characterised by large body size and an elongated snout. They have often been considered as eco-analogues of crocodilians based on superficial similarities. The slender-snouted Champsosaurus has been described as a 'gavial-like reptile', which implies it feeds underwater with a lateral swipe of the head and neck, as in the living slender-snouted crocodilians such as Gavialis gangeticus. In contrast, the short-snouted Simoedosaurus is often compared with short-snouted living crocodilians and is considered to take single prey items. However, the neck mobility and flexibility needed for feeding movements are poorly understood even in extant crocodilians. This study explores the relationship between cervical morphology and neck flexion, focusing particularly on lateral and dorsal movements in G. gangeticus by comparison with shorter-snouted crocodilians. The paper also describes a method to estimate the maximum angle of neck dorsiflexion in choristoderes based on the cervical morphology of extant crocodilian species. Three indices were used in this study, of which Index 3 is newly proposed, to compare cervical morphology and intervertebral joint flexibility: (1) Enclosed zygapophyseal angles (EZA) as an index of dorsoventral/ bilateral flexibility, (2) moment arm (M) of dorsiflexor muscles as an Index of resistance against ventroflexion and (3) the orientations of zygapophysial facets for a maximum angle of dorsiflexion. These Indices were validated using µCT scanning of fresh specimens of G. gangeticus and Caiman latirostris in lateral and dorsal flexion. A unique mechanism of lateral flexion was identified in G. gangeticus that uses a combination of the following features: (1) lateral flexion mainly restricted to the anterior cervical vertebrae (v2/v3: high EZA, with more horizontal zygapophyses) and (2) high degree of dorsiflexion at the v3/v4 and v4/v5 joints with potential for dorsal flexibility through the middle-posterior neck, which is used in inertial feeding. In contrast, Champsosaurus and Simoedosaurus possess relatively short cervical vertebrae, as in short-snouted crocodilians. The middle-posterior cervical vertebrae of Champsosaurus are specialised for lateral flexion (high EZA), and there is only limited capacity for dorsiflexion throughout the neck. Like G. gangeticus, therefore, Champsosaurus may have used its slender snout to grab fish from shoals using lateral sweeping motions of the head and neck, but the movement is through the neck, not the craniocervical joint. However, inertial feeding is less likely to have occurred in this genus, and the aligned palatal dentition may have aided the lingual transport of prey into the mouth. Simoedosaurus, on the other hand, appears to have been less specialised, with a neck that combined lateral and dorsolateral flexion, a move that could have been effective in catching both terrestrial and aquatic prey. Where these two choristoderan genera occurred in the same place, they may have divided their niche by prey types.
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Affiliation(s)
- Ryoko Matsumoto
- Kanagawa Prefectural Museum of Natural HistoryOdawaraKanagawaJapan
| | | | - Susan E. Evans
- Centre for Integrative AnatomyDepartment of Cell and Developmental BiologyUCLUniversity College LondonLondonUK
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6
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Brownstein CD. High morphological disparity in a bizarre Paleocene fauna of predatory freshwater reptiles. BMC Ecol Evol 2022; 22:34. [PMID: 35313822 PMCID: PMC8935759 DOI: 10.1186/s12862-022-01985-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/04/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The consequences of the K-Pg mass extinction are reflected across present biodiversity, but many faunas that appeared immediately after the extinction event were very different from current ones. Choristodera is a clade of reptiles of uncertain phylogenetic placement that have an extremely poor fossil record throughout their 150-million-year history. Yet, choristoderes survived the K-Pg event and persisted until the Miocene. RESULTS I describe the skulls and skeletons of two new choristoderes from a single Paleocene ecosystem in western North America that reveal the hidden Cenozoic diversity of this reptile clade. Despite their similar size, the new species deviate dramatically in morphology. Kosmodraco magnicornis gen. et sp. nov. possesses an extremely short snout and extensive cranial ornamentation. The sacrum of K. magnicornis bears enlarged muscle attachment sites and other modifications reminiscent of some giant crocodylians. In contrast, Champsosaurus norelli sp. nov. is a longirostrine species with an uninflated and ventrally divergent postorbital skull. Together with a North American choristodere previously classified in the European genus Simoedosaurus, K. magnicornis substantiates a new clade of giant, short-snouted taxa endemic to the Americas. C. norelli is found to be an early-diverging member of the genus Champsosaurus from the Cretaceous-Paleogene of the northern hemisphere. This suggests the presence of several ghost lineages of champsosaurid that crossed the K-Pg boundary. CONCLUSIONS The new taxa greatly increase Cenozoic choristodere richness and strengthen the evidence for the existence of distinctive freshwater faunas in Paleogene Eurasia and North America, where this clade diversified to exploit newly available macropredatory niches in the aftermath of the asteroid impact. The new choristoderes also reveal the distinct ecological context in which extant freshwater predators of the Americas like alligatoroids and gars have their origins: Paleocene fluviolacustrine ecosystems in North America displayed high large predator diversity and morphological disparity relative to modern ones.
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Affiliation(s)
- Chase Doran Brownstein
- Stamford Museum and Nature Center, Stamford, CT, USA. .,Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA.
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7
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Brocklehurst N, Ford DP, Benson RBJ. Early origins of divergent patterns of morphological evolution on the mammal and reptile stem-lineages. Syst Biol 2022; 71:1195-1209. [PMID: 35274702 PMCID: PMC9366456 DOI: 10.1093/sysbio/syac020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/09/2022] [Accepted: 03/05/2022] [Indexed: 11/28/2022] Open
Abstract
The origin of amniotes 320 million years ago signaled independence from water in vertebrates and was closely followed by divergences within the mammal and reptile stem lineages (Synapsida and Reptilia). Early members of both groups had highly similar morphologies, being superficially “lizard-like” forms with many plesiomorphies. However, the extent to which they might have exhibited divergent patterns of evolutionary change, with the potential to explain the large biological differences between their living members, is unresolved. We use a new, comprehensive phylogenetic dataset to quantify variation in rates and constraints of morphological evolution among Carboniferous–early Permian amniotes. We find evidence for an early burst of evolutionary rates, resulting in the early origins of morphologically distinctive subgroups that mostly persisted through the Cisuralian. Rates declined substantially through time, especially in reptiles. Early reptile evolution was also more constrained compared with early synapsids, exploring a more limited character state space. Postcranial innovation in particular was important in early synapsids, potentially related to their early origins of large body size. In contrast, early reptiles predominantly varied the temporal region, suggesting disparity in skull and jaw kinematics, and foreshadowing the variability of cranial biomechanics seen in reptiles today. Our results demonstrate that synapsids and reptiles underwent an early divergence of macroevolutionary patterns. This laid the foundation for subsequent evolutionary events and may be critical in understanding the substantial differences between mammals and reptiles today. Potential explanations include an early divergence of developmental processes or of ecological factors, warranting cross-disciplinary investigation. [Amniote; body size; constraint; phylogeny; rate.]
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Affiliation(s)
- Neil Brocklehurst
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, UK
| | - David P Ford
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, UK
| | - Roger B J Benson
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, UK
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8
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Kavková M, Šulcová M, Zikmund T, Pyszko M, Kaiser J, Buchtová M. X-ray microtomography imaging of craniofacial hard tissues in selected reptile species with different types of dentition. Gigascience 2022; 11:6543636. [PMID: 35254425 PMCID: PMC8900495 DOI: 10.1093/gigascience/giac016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/19/2021] [Accepted: 01/28/2022] [Indexed: 12/23/2022] Open
Abstract
Background Reptiles exhibit a large heterogeneity in teeth morphology. The main variability comprises the different tooth shape, the type of tooth attachment to the underlying bone, or the ability to replace the teeth. Findings Here, we provide full datasets of microtomography scans and 3D models of reptilian dentitions and skulls. We selected representative species for each of 9 reptilian families on the basis of their characteristic dental features. Because there are ≥4 different types of tooth-bone attachments, ranging from the mammalian-like thecodont attachment found in crocodilians to the simple acrodont implantation observed in some lizards, we aimed to evaluate species with different types of tooth-bone attachments. Moreover, another interesting feature varying in reptilian species is the complexity of tooth shape or the number of tooth generations, which can be associated with the type of tooth attachment to the jawbone. Therefore, selected model species also include animals with distinct tooth morphology along the jaw or different number of tooth generations. The development of tooth attachment and relationship of the tooth to the jaw can be further analysed in detail on a large collection of pre-hatching stages of chameleon. Next, we introduce different possibilities for how these datasets can be further used to study tooth-bone relationships or tooth morphology in 3D space. Moreover, these datasets can be valuable for additional morphological and morphometric analyses of reptilian skulls or their individually segmented skeletal elements. Conclusions Our collection of microcomputed tomography scans can bring new insight into dental or skeletal research. The broad selection of reptilian species, together with their unique dental features and high quality of these scans including complete series of developmental stages of our model species and provide large opportunities for their reuse. Scans can be further used for virtual reality, 3D printing, or in education.
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Affiliation(s)
- Michaela Kavková
- Central European Institute of Technology, Brno University of Technology, 616 69 Brno, Czech Republic
| | - Marie Šulcová
- Department of Experimental Biology, Faculty of Science, Masaryk University, 612 42 Brno, Czech Republic.,Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, v.v.i., Czech Academy of Sciences, 602 00 Brno, Czech Republic
| | - Tomáš Zikmund
- Central European Institute of Technology, Brno University of Technology, 616 69 Brno, Czech Republic
| | - Martin Pyszko
- Department of Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Veterinary Sciences Brno, 625 00 Brno, Czech Republic
| | - Jozef Kaiser
- Central European Institute of Technology, Brno University of Technology, 616 69 Brno, Czech Republic
| | - Marcela Buchtová
- Department of Experimental Biology, Faculty of Science, Masaryk University, 612 42 Brno, Czech Republic.,Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, v.v.i., Czech Academy of Sciences, 602 00 Brno, Czech Republic
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9
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Yin YL, Ji C, Zhou M. The anatomy of the palate in Early Triassic Chaohusaurus brevifemoralis (Reptilia: Ichthyosauriformes) based on digital reconstruction. PeerJ 2021; 9:e11727. [PMID: 34268013 PMCID: PMC8269639 DOI: 10.7717/peerj.11727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/15/2021] [Indexed: 12/20/2022] Open
Abstract
The palatal anatomy of ichthyosauriforms remains largely unknown. Here, the complete palate of the early-branching ichthyosauriform Chaohusaurus brevifemoralis is reconstructed and described for the first time with the assistance of high-resolution X-ray computed tomography (CT) scanning on the basis of the three-dimensionally preserved skull of its paratype (GMPKU-P-3086) from the Lower Triassic of South China. The reconstruction reveals new palatal features of C. brevifemoralis. The palatine contacts the jugal directly, which is observed in ichthyosauriforms for the first time. A single row of denticles is present on each side of the palate. The vomer exceeds the anterior and posterior margins of the internal naris. The pterygoid is posterior to the internal naris. The epipterygoid is present and the ectopterygoid is absent.
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Affiliation(s)
- Ya-Lei Yin
- Department of Geology and Geological Museum, Peking University, Beijing, China
| | - Cheng Ji
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China
| | - Min Zhou
- Department of Geology and Geological Museum, Peking University, Beijing, China
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10
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Hovorakova M, Zahradnicek O, Bartos M, Hurnik P, Stransky J, Stembirek J, Tucker AS. Reawakening of Ancestral Dental Potential as a Mechanism to Explain Dental Pathologies. Integr Comp Biol 2021; 60:619-629. [PMID: 32492167 DOI: 10.1093/icb/icaa053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
During evolution, there has been a trend to reduce both the number of teeth and the location where they are found within the oral cavity. In mammals, the formation of teeth is restricted to a horseshoe band of odontogenic tissue, creating a single dental arch on the top and bottom of the jaw. Additional teeth and structures containing dental tissue, such as odontogenic tumors or cysts, can appear as pathologies. These tooth-like structures can be associated with the normal dentition, appearing within the dental arch, or in nondental areas. The etiology of these pathologies is not well elucidated. Reawakening of the potential to form teeth in different parts of the oral cavity could explain the origin of dental pathologies outside the dental arch, thus such pathologies are a consequence of our evolutionary history. In this review, we look at the changing pattern of tooth formation within the oral cavity during vertebrate evolution, the potential to form additional tooth-like structures in mammals, and discuss how this knowledge shapes our understanding of dental pathologies in humans.
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Affiliation(s)
- Maria Hovorakova
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University in Prague, Albertov 4, 128 00 Prague 2, Czech Republic.,Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Oldrich Zahradnicek
- Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Martin Bartos
- Department of Stomatology, First Faculty of Medicine, Charles University, General University Hospital in Prague, Katerinska 32, 12801 Prague 2, Czech Republic.,Institute of Anatomy, First Faculty of Medicine, Charles University, U Nemocnice 3, Prague 2, 128 00, Czech Republic
| | - Pavel Hurnik
- Department of Pathology, University Hospital Ostrava, 17. listopadu 1790, Ostrava-Poruba, 708 52, Czech Republic.,Department of Pathology at Faculty of Medicine, University of Ostrava, Syllabova 19, Ostrava-Zabreh, 703 00, Czech Republic
| | - Jiri Stransky
- Department of Oral and Maxillofacial Surgery, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava-Poruba, Czech Republic
| | - Jan Stembirek
- Department of Oral and Maxillofacial Surgery, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava-Poruba, Czech Republic.,Institute of Animal Physiology and Genetics, v.v.i., Czech Academy of Sciences, Veveri 97, 602 00, Brno 2, Czech Republic
| | - Abigail S Tucker
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK
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11
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Paluh DJ, Riddell K, Early CM, Hantak MM, Jongsma GFM, Keeffe RM, Magalhães Silva F, Nielsen SV, Vallejo-Pareja MC, Stanley EL, Blackburn DC. Rampant tooth loss across 200 million years of frog evolution. eLife 2021; 10:e66926. [PMID: 34060471 PMCID: PMC8169120 DOI: 10.7554/elife.66926] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/12/2021] [Indexed: 01/06/2023] Open
Abstract
Teeth are present in most clades of vertebrates but have been lost completely several times in actinopterygian fishes and amniotes. Using phenotypic data collected from over 500 genera via micro-computed tomography, we provide the first rigorous assessment of the evolutionary history of dentition across all major lineages of amphibians. We demonstrate that dentition is invariably present in caecilians and salamanders, but teeth have been lost completely more than 20 times in frogs, a much higher occurrence of edentulism than in any other vertebrate group. The repeated loss of teeth in anurans is associated with a specialized diet of small invertebrate prey as well as shortening of the lower jaw, but it is not correlated with a reduction in body size. Frogs provide an unparalleled opportunity for investigating the molecular and developmental mechanisms of convergent tooth loss on a large phylogenetic scale.
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Affiliation(s)
- Daniel J Paluh
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
- Department of Biology, University of FloridaGainesvilleUnited States
| | - Karina Riddell
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
| | - Catherine M Early
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
- Biology Department, Science Museum of MinnesotaSaint PaulUnited States
| | - Maggie M Hantak
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
| | - Gregory FM Jongsma
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
| | - Rachel M Keeffe
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
- Department of Biology, University of FloridaGainesvilleUnited States
| | - Fernanda Magalhães Silva
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
- Programa de Pós Graduação em Zoologia, Universidade Federal do Pará, Museu Paraense Emilio GoeldiBelémBrazil
| | - Stuart V Nielsen
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
| | - María Camila Vallejo-Pareja
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
- Department of Biology, University of FloridaGainesvilleUnited States
| | - Edward L Stanley
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
| | - David C Blackburn
- Department of Natural History, Florida Museum of Natural History, University of FloridaGainesvilleUnited States
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12
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Soukup V, Tazaki A, Yamazaki Y, Pospisilova A, Epperlein HH, Tanaka EM, Cerny R. Oral and Palatal Dentition of Axolotl Arises From a Common Tooth-Competent Zone Along the Ecto-Endodermal Boundary. Front Cell Dev Biol 2021; 8:622308. [PMID: 33505974 PMCID: PMC7829593 DOI: 10.3389/fcell.2020.622308] [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: 10/28/2020] [Accepted: 12/02/2020] [Indexed: 11/13/2022] Open
Abstract
Vertebrate dentitions arise at various places within the oropharyngeal cavity including the jaws, the palate, or the pharynx. These dentitions develop in a highly organized way, where new tooth germs are progressively added adjacent to the initiator center, the first tooth. At the same time, the places where dentitions develop house the contact zones between the outer ectoderm and the inner endoderm, and this colocalization has instigated various suggestions on the roles of germ layers for tooth initiation and development. Here, we study development of the axolotl dentition, which is a complex of five pairs of tooth fields arranged into the typically tetrapod outer and inner dental arcades. By tracking the expression patterns of odontogenic genes, we reason that teeth of both dental arcades originate from common tooth-competent zones, one present on the mouth roof and one on the mouth floor. Progressive compartmentalization of these zones and a simultaneous addition of new tooth germs distinct for each prospective tooth field subsequently control the final shape and composition of the axolotl dentition. Interestingly, by following the fate of the GFP-labeled oral ectoderm, we further show that, in three out of five tooth field pairs, the first tooth develops right at the ecto-endodermal boundary. Our results thus indicate that a single tooth-competent zone gives rise to both dental arcades of a complex tetrapod dentition. Further, we propose that the ecto-endodermal boundary running through this zone should be accounted for as a potential source of instruction factors instigating the onset of the odontogenic program.
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Affiliation(s)
- Vladimír Soukup
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Akira Tazaki
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany.,Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
| | - Yosuke Yamazaki
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Anna Pospisilova
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | | | - Elly M Tanaka
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany.,Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
| | - Robert Cerny
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
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13
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Schwarz D, Gorb SN, Kovalev A, Konow N, Heiss E. Flexibility of intraoral food processing in the salamandrid newt Triturus carnifex: effects of environment and prey type. J Exp Biol 2020; 223:jeb232868. [PMID: 32968002 DOI: 10.1242/jeb.232868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/09/2020] [Indexed: 11/20/2022]
Abstract
Intraoral food processing mechanisms are known for all major vertebrate groups, but the form and function of systems used to crush, grind or puncture food items can differ substantially between and within groups. Most vertebrates display flexible mechanisms of intraoral food processing with respect to different environmental conditions or food types. It has recently been shown that newts use cyclical loop-motions of the tongue to rasp prey against the palatal dentition. However, it remains unknown whether newts can adjust their food processing behavior in response to different food types or environmental conditions. Newts are interesting models for studying the functional adaptation to different conditions because of their unique and flexible lifestyle: they seasonally change between aquatic and terrestrial habitats, adapt their prey-capture mode to the respective environment, and consume diverse food types with different mechanical properties. Using X-ray high-speed recordings, anatomical investigations, behavioral analyses and mechanical property measurements, we tested the effects of the medium in which feeding occurs (water/air) and the food type (maggot, earthworm, cricket) on the processing behavior in Triturus carnifex We discovered that food processing, by contrast to prey capture, differed only slightly between aquatic and terrestrial habitats. However, newts adjusted the number of processing cycles to different prey types: while maggots were processed extensively, earthworm pieces were barely processed at all. We conclude that, in addition to food mechanical properties, sensory feedback such as smell and taste appear to induce flexible processing responses, while the medium in which feeding occurs appears to have less of an effect.
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Affiliation(s)
- Daniel Schwarz
- Institute of Zoology and Evolutionary Research, Friedrich Schiller University Jena, Erbertstraße 1, 07743 Jena, Germany
| | - Stanislav N Gorb
- Zoological Institute, Kiel University, am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Alexander Kovalev
- Zoological Institute, Kiel University, am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Nicolai Konow
- Department of Biological Sciences, University of Massachusetts Lowell., 198 Riverside Street, Lowell, MA 01854, USA
| | - Egon Heiss
- Institute of Zoology and Evolutionary Research, Friedrich Schiller University Jena, Erbertstraße 1, 07743 Jena, Germany
- Ark-Biodiversity, Willdenowstraße 6, 12203 Berlin, Germany
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14
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Cranial morphology of the tanystropheid Macrocnemus bassanii unveiled using synchrotron microtomography. Sci Rep 2020; 10:12412. [PMID: 32709952 PMCID: PMC7381672 DOI: 10.1038/s41598-020-68912-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 07/03/2020] [Indexed: 11/08/2022] Open
Abstract
The genus Macrocnemus is a member of the Tanystropheidae, a clade of non-archosauriform archosauromorphs well known for their very characteristic, elongated cervical vertebrae. Articulated specimens are known from the Middle Triassic of Alpine Europe and China. Although multiple articulated specimens are known, description of the cranial morphology has proven challenging due to the crushed preservation of the specimens. Here we use synchrotron micro computed tomography to analyse the cranial morphology of a specimen of the type species Macrocnemus bassanii from the Besano Formation of Monte San Giorgio, Ticino, Switzerland. The skull is virtually complete and we identify and describe the braincase and palatal elements as well the atlas-axis complex for the first time. Moreover, we add to the knowledge of the morphology of the skull roof, rostrum and hemimandible, and reconstruct the cranium of M. bassanii in 3D using the rendered models of the elements. The circumorbital bones were found to be similar in morphology to those of the archosauromorphs Prolacerta broomi and Protorosaurus speneri. In addition, we confirm the palatine, vomer and pterygoid to be tooth-bearing palatal bones, but also observed heterodonty on the pterygoid and the palatine.
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15
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Sookias RB, Dilkes D, Sobral G, Smith RMH, Wolvaardt FP, Arcucci AB, Bhullar BAS, Werneburg I. The craniomandibular anatomy of the early archosauriform Euparkeria capensis and the dawn of the archosaur skull. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200116. [PMID: 32874620 PMCID: PMC7428278 DOI: 10.1098/rsos.200116] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 06/22/2020] [Indexed: 05/15/2023]
Abstract
Archosauria (birds, crocodilians and their extinct relatives) form a major part of terrestrial ecosystems today, with over 10 000 living species, and came to dominate the land for most of the Mesozoic (over 150 Myr) after radiating following the Permian-Triassic extinction. The archosaur skull has been essential to this diversification, itself diversified into myriad forms. The archosauriform Euparkeria capensis from the Middle Triassic (Anisian) of South Africa has been of great interest since its initial description in 1913, because its anatomy shed light on the origins and early evolution of crown Archosauria and potentially approached that of the archosaur common ancestor. Euparkeria has been widely used as an outgroup in phylogenetic analyses and when investigating patterns of trait evolution among archosaurs. Although described monographically in 1965, subsequent years have seen great advances in the understanding of early archosaurs and in imaging techniques. Here, the cranium and mandible of Euparkeria are fully redescribed and documented using all fossil material and computed tomographic data. Details previously unclear are fully described, including vomerine dentition, the epiptergoid, number of premaxillary teeth and palatal arrangement. A new diagnosis and cranial and braincase reconstruction is provided, and an anatomical network analysis is performed on the skull of Euparkeria and compared with other amniotes. The modular composition of the cranium suggests a flexible skull well adapted to feeding on agile food, but with a clear tendency towards more carnivorous behaviour, placing the taxon at the interface between ancestral diapsid and crown archosaur ecomorphology, corresponding to increases in brain size, visual sensitivity, upright locomotion and metabolism around this point in archosauriform evolution. The skull of Euparkeria epitomizes a major evolutionary transition, and places crown archosaur morphology in an evolutionary context.
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Affiliation(s)
- Roland B. Sookias
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115 Berlin, Germany
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| | - David Dilkes
- Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI 54901, USA
| | - Gabriela Sobral
- Staatliches Museum für Naturkunde, Rosenstein 1, 70191 Stuttgart, Germany
| | - Roger M. H. Smith
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
- Iziko South African Museum, PO Box 61, Cape Town, South Africa
| | - Frederik P. Wolvaardt
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
| | - Andrea B. Arcucci
- IMIBIO CONICET Universidad Nacional de San Luis, Av Ejercito de los Andes 950, 5700 San Luis, Argentina
| | - Bhart-Anjan S. Bhullar
- Department of Earth and Planetary Sciences, 210 Whitney Ave., Yale University, New Haven, CT 06511, USA
- Yale Peabody Museum of Natural History, 170 Whitney Ave., New Haven, CT 06511, USA
| | - Ingmar Werneburg
- Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) at Eberhard-Karls-Universität, Sigwartstraße 10, 72076 Tübingen, Germany
- Fachbereich Geowissenschaften der Eberhard-Karls-Universität Tübingen, Hölderlinstraße 12, 72074 Tübingen, Germany
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Evolution, Diversity, and Development of the Craniocervical System in Turtles with Special Reference to Jaw Musculature. HEADS, JAWS, AND MUSCLES 2019. [DOI: 10.1007/978-3-319-93560-7_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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