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Nicklin EF, Cohen KE, Cooper RL, Mitchell G, Fraser GJ. Evolution, development, and regeneration of tooth-like epithelial appendages in sharks. Dev Biol 2024; 516:221-236. [PMID: 39154741 DOI: 10.1016/j.ydbio.2024.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 08/05/2024] [Accepted: 08/15/2024] [Indexed: 08/20/2024]
Abstract
Sharks and their relatives are typically covered in highly specialized epithelial appendages embedded in the skin called dermal denticles; ancient tooth-like units (odontodes) composed of dentine and enamel-like tissues. These 'skin teeth' are remarkably similar to oral teeth of vertebrates and share comparable morphological and genetic signatures. Here we review the histological and morphological data from embryonic sharks to uncover characters that unite all tooth-like elements (odontodes), including teeth and skin denticles in sharks. In addition, we review the differences between the skin and oral odontodes that reflect their varied capacity for renewal. Our observations have begun to decipher the developmental and genetic shifts that separate these seemingly similar dental units, including elements of the regenerative nature in both oral teeth and the emerging skin denticles from the small-spotted catshark (Scyliorhinus canicula) and other chondrichthyan models. Ultimately, we ask what defines a tooth at both the molecular and morphological level. These insights aim to help us understand how nature makes, replaces and evolves a vast array of odontodes.
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Affiliation(s)
- Ella F Nicklin
- Department of Biology, University of Florida, Gainesville, USA
| | - Karly E Cohen
- Department of Biology, University of Florida, Gainesville, USA; Department of Biology, California State University Fullerton, Fullerton, USA
| | - Rory L Cooper
- Department of Genetics and Evolution, University of Geneva, Switzerland
| | - Gianna Mitchell
- Department of Biology, University of Florida, Gainesville, USA
| | - Gareth J Fraser
- Department of Biology, University of Florida, Gainesville, USA.
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2
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Jambura PL, Villalobos-Segura E, Türtscher J, Begat A, Staggl MA, Stumpf S, Kindlimann R, Klug S, Lacombat F, Pohl B, Maisey JG, Naylor GJP, Kriwet J. Systematics and Phylogenetic Interrelationships of the Enigmatic Late Jurassic Shark Protospinax annectans Woodward, 1918 with Comments on the Shark-Ray Sister Group Relationship. DIVERSITY 2023; 15:311. [PMID: 36950326 PMCID: PMC7614347 DOI: 10.3390/d15030311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The Late Jurassic elasmobranch Protospinax annectans is often regarded as a key species to our understanding of crown group elasmobranch interrelationships and the evolutionary history of this group. However, since its first description more than 100 years ago, its phylogenetic position within the Elasmobranchii (sharks and rays) has proven controversial, and a closer relationship between Protospinax and each of the posited superorders (Batomorphii, Squalomorphii, and Galeomorphii) has been proposed over the time. Here we revise this controversial taxon based on new holomorphic specimens from the Late Jurassic Konservat-Lagerstätte of the Solnhofen Archipelago in Bavaria (Germany) and review its skeletal morphology, systematics, and phylogenetic interrelationships. A data matrix with 224 morphological characters was compiled and analyzed under a molecular backbone constraint. Our results indicate a close relationship between Protospinax, angel sharks (Squatiniformes), and saw sharks (Pristiophoriformes). However, the revision of our morphological data matrix within a molecular framework highlights the lack of morphological characters defining certain groups, especially sharks of the order Squaliformes, hampering the phylogenetic resolution of Protospinax annectans with certainty. Furthermore, the monophyly of modern sharks retrieved by molecular studies is only weakly supported by morphological data, stressing the need for more characters to align morphological and molecular studies in the future.
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Affiliation(s)
- Patrick L. Jambura
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
- Correspondence:
| | | | - Julia Türtscher
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Arnaud Begat
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Manuel Andreas Staggl
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Sebastian Stumpf
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
| | - René Kindlimann
- Haimuseum und Sammlung R. Kindlimann, 8607 Aathal-Seegräben, Switzerland
| | - Stefanie Klug
- School of Science (GAUSS), Georg–August Universität Göttingen, 37077 Göttingen, Germany
| | | | - Burkhard Pohl
- Interprospekt Group, 1724 Ferpicloz, Switzerland
- Wyoming Dinosaur Center, Thermopolis, WY 82443, USA
| | - John G. Maisey
- Department of Vertebrate Paleontology, American Natural History Museum, New York, NY 10024, USA
| | - Gavin J. P. Naylor
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Jürgen Kriwet
- Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
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3
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Wang D, Han S, Yang M. Tooth Diversity Underpins Future Biomimetic Replications. Biomimetics (Basel) 2023; 8:biomimetics8010042. [PMID: 36810373 PMCID: PMC9944091 DOI: 10.3390/biomimetics8010042] [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: 12/26/2022] [Revised: 01/14/2023] [Accepted: 01/15/2023] [Indexed: 01/20/2023] Open
Abstract
Although the evolution of tooth structure seems highly conserved, remarkable diversity exists among species due to different living environments and survival requirements. Along with the conservation, this diversity of evolution allows for the optimized structures and functions of teeth under various service conditions, providing valuable resources for the rational design of biomimetic materials. In this review, we survey the current knowledge about teeth from representative mammals and aquatic animals, including human teeth, herbivore and carnivore teeth, shark teeth, calcite teeth in sea urchins, magnetite teeth in chitons, and transparent teeth in dragonfish, to name a few. The highlight of tooth diversity in terms of compositions, structures, properties, and functions may stimulate further efforts in the synthesis of tooth-inspired materials with enhanced mechanical performance and broader property sets. The state-of-the-art syntheses of enamel mimetics and their properties are briefly covered. We envision that future development in this field will need to take the advantage of both conservation and diversity of teeth. Our own view on the opportunities and key challenges in this pathway is presented with a focus on the hierarchical and gradient structures, multifunctional design, and precise and scalable synthesis.
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Cook TD, Prothero J, Brudy M, Magraw JA. Complex enameloid microstructure of †Ischyrhiza mira rostral denticles. J Anat 2022; 241:616-627. [PMID: 35445396 PMCID: PMC9358731 DOI: 10.1111/joa.13676] [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: 02/23/2022] [Revised: 04/07/2022] [Accepted: 04/07/2022] [Indexed: 11/30/2022] Open
Abstract
Serving in a foraging or self-defense capacity, pristiophorids, pristids, and the extinct sclerorhynchoids independently evolved an elongated rostrum lined with modified dermal denticles called rostral denticles. Isolated rostral denticles of the sclerorhynchoid Ischyrhiza mira are commonly recovered from Late Cretaceous North American marine deposits. Although the external morphology has been thoroughly presented in the literature, very little is known about the histological composition and organization of these curious structures. Using acid-etching techniques and scanning electron microscopy, we show that the microstructure of I. mira rostral denticles are considerably more complex than that of previously described dermal denticles situated elsewhere on the body. The apical cap consists of outer single crystallite enameloid (SCE) and inner bundled crystallite enameloid (BCE) overlying a region of orthodentine. The BCE has distinct parallel bundled enameloid (PBE), tangled bundled enameloid (TBE), and radial bundled enameloid (RBE) components. Additionally, the cutting edge of the rostral denticle is produced by a superficial layer of SCE and a deeper ridges/cutting edge layer (RCEL) of the BCE. The highly organized enameloid observed in the rostral denticles of this batomorph resembles that of the multifaceted tissue architecture observed in the oral teeth of selachimorphs and demonstrates that dermal scales have the capacity to evolve histologically similar complex tooth-like structures both inside and outside the oropharyngeal cavity.
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Affiliation(s)
- Todd D. Cook
- Penn State BehrendSchool of ScienceEriePennsylvaniaUSA
| | - Jack Prothero
- Penn State BehrendSchool of ScienceEriePennsylvaniaUSA
| | - Michael Brudy
- Penn State BehrendSchool of ScienceEriePennsylvaniaUSA
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Jambura PL, Stumpf S, Kriwet J. Skeletal remains of the oldest known pseudocoracid shark Pseudocorax kindlimanni sp. nov. (Chondrichthyes, Lamniformes) from the Late Cretaceous of Lebanon. CRETACEOUS RESEARCH 2021; 125:104842. [PMID: 34642522 PMCID: PMC7611798 DOI: 10.1016/j.cretres.2021.104842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A new fossil mackerel shark, Pseudocorax kindlimanni sp. nov. (Lamniformes, Pseudocoracidae), is described from the Cenomanian Konservat-Lagerstätte of Haqel, Lebanon. The new species is based on the most complete fossil of this group to date, which comprises an associated tooth set of 70 teeth, six articulated vertebral centra, numerous placoid scales and pieces of unidentifiable mineralized cartilage. The dentition of P. kindlimanni sp. nov. is marked by a high degree of monognathic heterodonty but does not exhibit the characteristic "lamnoid tooth pattern" known from other macrophagous lamniform sharks. In addition, P. kindlimanni sp. nov. shows differences in tooth microstructure and vertebral centrum morphology compared to other lamniform sharks. These variations, however, are also known from other members of this order and do not warrant the assignment of Pseudocorax outside the lamniform sharks. The new fossil is the oldest known pseudocoracid shark and pushes the origin of this group back into the Cenomanian, a time when lamniform sharks underwent a major diversification. This radiation resulted not only in high species diversity, but also in the development of a diverse array of morphological traits and adaptation to different ecological niches. Pseudocorax kindlimanni sp. nov. was a small, active predator capable of fast swimming, and it occupied the lower trophic levels of the marine food web in the Late Cretaceous.
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Wilmers J, Waldron M, Bargmann S. Hierarchical Microstructure of Tooth Enameloid in Two Lamniform Shark Species, Carcharias taurus and Isurus oxyrinchus. NANOMATERIALS 2021; 11:nano11040969. [PMID: 33918809 PMCID: PMC8070439 DOI: 10.3390/nano11040969] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 12/22/2022]
Abstract
Shark tooth enameloid is a hard tissue made up of nanoscale fluorapatite crystallites arranged in a unique hierarchical pattern. This microstructural design results in a macroscopic material that is stiff, strong, and tough, despite consisting almost completely of brittle mineral. In this contribution, we characterize and compare the enameloid microstructure of two modern lamniform sharks, Isurus oxyrinchus (shortfin mako shark) and Carcharias taurus (spotted ragged-tooth shark), based on scanning electron microscopy images. The hierarchical microstructure of shark enameloid is discussed in comparison with amniote enamel. Striking similarities in the microstructures of the two hard tissues are found. Identical structural motifs have developed on different levels of the hierarchy in response to similar biomechanical requirements in enameloid and enamel. Analyzing these structural patterns allows the identification of general microstructural design principles and their biomechanical function, thus paving the way for the design of bioinspired composite materials with superior properties such as high strength combined with high fracture resistance.
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Affiliation(s)
- Jana Wilmers
- Chair of Solid Mechanics, University of Wuppertal, 42119 Wuppertal, Germany;
- Correspondence: ; Tel.: +49-202-439-2086
| | - Miranda Waldron
- Electron Microscope Unit, University of Cape Town, Cape Town 7701, South Africa;
| | - Swantje Bargmann
- Chair of Solid Mechanics, University of Wuppertal, 42119 Wuppertal, Germany;
- Wuppertal Center for Smart Materials, University of Wuppertal, 42119 Wuppertal, Germany
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Tütken T, Weber M, Zohar I, Helmy H, Bourgon N, Lernau O, Jochum KP, Sisma-Ventura G. Strontium and Oxygen Isotope Analyses Reveal Late Cretaceous Shark Teeth in Iron Age Strata in the Southern Levant. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.570032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Skeletal remains in archaeological strata are often assumed to be of similar ages. Here we show that combined Sr and O isotope analyses can serve as a powerful tool for assessing fish provenance and even for identifying fossil fish teeth in archaeological contexts. For this purpose, we established a reference Sr and O isotope dataset of extant fish teeth from major water bodies in the Southern Levant. Fossil shark teeth were identified within Iron Age cultural layers dating to 8–9th century BCE in the City of David, Jerusalem, although the reason for their presence remains unclear. Their enameloid 87Sr/86Sr and δ18OPO4 values [0.7075 ± 0.0001 (1 SD, n = 7) and 19.6 ± 0.9‰ (1 SD, n = 6), respectively], are both much lower than values typical for modern marine sharks from the Mediterranean Sea [0.7092 and 22.5–24.6‰ (n = 2), respectively]. The sharks’ 87Sr/86Sr are also lower than those of rain- and groundwater as well as the main soil types in central Israel (≥0.7079). This indicates that these fossil sharks incorporated Sr (87Sr/86Sr ≈ 0.7075) from a marine habitat with values typical for Late Cretaceous seawater. This scenario is in line with the low shark enameloid δ18OPO4 values reflecting tooth formation in the warm tropical seawater of the Tethys Ocean. Age estimates using 87Sr/86Sr stratigraphy place these fossil shark teeth at around 80-million-years-old. This was further supported by their taxonomy and the high dentine apatite crystallinity, low organic carbon, high U and Nd contents, characteristics that are typical for fossil specimens, and different from those of archaeological Gilthead seabream (Sparus aurata) teeth from the same cultural layers and another Chalcolithic site (Gilat). Chalcolithic and Iron Age seabream enameloid has seawater-like 87Sr/86Sr of 0.7091 ± 0.0001 (1 SD, n = 6), as expected for modern marine fish. Fossil shark and archaeological Gilthead seabream teeth both preserve original, distinct enameloid 87Sr/86Sr and δ18OPO4 signatures reflecting their different aquatic habitats. Fifty percent of the analysed Gilthead seabream teeth derive from hypersaline seawater, indicating that these seabreams were exported from the hypersaline Bardawil Lagoon in Sinai (Egypt) to the Southern Levant since the Iron Age period and possibly even earlier.
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8
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Fellah C, Douillard T, Maire E, Meille S, Reynard B, Cuny G. 3D microstructural study of selachimorph enameloid evolution. J Struct Biol 2020; 213:107664. [PMID: 33221390 DOI: 10.1016/j.jsb.2020.107664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/12/2020] [Accepted: 11/14/2020] [Indexed: 10/22/2022]
Abstract
Enameloid, the hyper-mineralized tissue covering shark teeth is a complex structure resulting from both ameloblast and odontoblast activity. The way these two types of cells interact to set up this tissue is not fully understood and results in the formation of subunits in the enameloid: the Single Crystallite Enameloid (SCE) and the Bundled Crystallite Enameloid (BCE). Using the Focused Ion Beam Nanotomography (FIB-nt), 3D images were produced to assess the relationship between the SCE and BCE of one fossil and one recent neoselachian shark teeth. 3D analysis of crystallite bundles reveals a strong connection between the crystallites forming the SCE and those forming the bundles of the Radial Bundle Enameloid (RBE), a component of the BCE, although it has been suggested that SCE and BCE have a different origin: epithelial for the SCE and mesenchymal for the BCE. Another significant result of the use of FIB-nt is the visualization of frequent branching among the radial bundles forming the RBE, including horizontal link between adjacent bundles. FIB-nt demonstrates therefore a strong potential to decipher the complex evolution of hyper-mineralised tissue in shark teeth, and, therefore, to better understand the evolution of tooth structure among basal Gnathostomes.
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Affiliation(s)
- C Fellah
- Université de Lyon, ENS Lyon, Université Lyon 1, CNRS, LGL-TPE, F-69007 Lyon, France.
| | - T Douillard
- Université de Lyon, INSA-Lyon, UMR CNRS 5510 MATEIS, Villeurbanne Cedex, France
| | - E Maire
- Université de Lyon, INSA-Lyon, UMR CNRS 5510 MATEIS, Villeurbanne Cedex, France
| | - S Meille
- Université de Lyon, INSA-Lyon, UMR CNRS 5510 MATEIS, Villeurbanne Cedex, France
| | - B Reynard
- Université de Lyon, ENS Lyon, Université Lyon 1, CNRS, LGL-TPE, F-69007 Lyon, France
| | - G Cuny
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69622, Villeurbanne, France
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Moyer JK, Finucci B, Riccio ML, Irschick DJ. Dental morphology and microstructure of the Prickly Dogfish Oxynotus bruniensis (Squaliformes: Oxynotidae). J Anat 2020; 237:916-932. [PMID: 32539172 DOI: 10.1111/joa.13251] [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: 03/24/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 11/25/2022] Open
Abstract
This study describes and illustrates the jaws, teeth, and tooth microstructure of the Prickly Dogfish Oxynotus bruniensis. Detailed accounts of the dental morphology of O. bruniensis are rare and have not addressed the tissue arrangement or microstructure of the teeth. These features are documented and discussed in the contexts of interspecific comparisons with other elasmobranchs and the dietary specialization of O. bruniensis. The overall tooth morphology of O. bruniensis is similar to those of other closely related members in the order Squaliformes, as is the tissue arrangement, or histotype. Oxynotus bruniensis exhibits a simplified enameloid microstructure, which we compare with previously documented enameloid microstructures of other elasmobranchs. Though subtle interspecific differences in dental characters are documented, neither overall tooth morphology nor histotype and microstructure are unique to O. bruniensis. We conclude that in the case of O. bruniensis, dietary specialization is facilitated by behavioral rather than morphological specialization.
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Affiliation(s)
- Joshua K Moyer
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Brittany Finucci
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | | | - Duncan J Irschick
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts Amherst, Amherst, MA, USA.,Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
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Meredith Smith M, Underwood C, Goral T, Healy C, Johanson Z. Growth and mineralogy in dental plates of the holocephalan Harriotta raleighana (Chondrichthyes): novel dentine and conserved patterning combine to create a unique chondrichthyan dentition. ZOOLOGICAL LETTERS 2019; 5:11. [PMID: 30923631 PMCID: PMC6419362 DOI: 10.1186/s40851-019-0125-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
ABSTRACT The dentition in extant holocephalans (Chondrichthyes) comprises three pairs of continuously growing dental plates, rather than the separate teeth characterizing elasmobranchs. We investigated how different types of dentine in these plates, including hypermineralized dentine, are arranged, and how this is renewed aborally, in adult and juvenile dentitions of Harriotta raleighana (Rhinochimeridae). Individual plates were analysed using x-ray computed tomography (μCT), scanning electron microscopy (SEM) in back scattered mode with energy dispersive X-ray (EDX) analysis, and optical microscopy on hard tissue sections. RESULTS Harriotta dental plates are made entirely of dentine tissue, mostly as trabecular dentine, bone itself being absent. Hypermineralized dentine forms in restricted ovoid and tritor spaces within trabecular dentine, inside a shell of outer and inner dentine layers. Trabecular dentine is ubiquitous but changes to sclerotic osteodentine near the oral surface by increasing density, remaining less mineralized than the hypermineralized dentine. All structures are renewed aborally, within a vascular dental pulp, a tissue suggested to be a source of stem cells for tissue renewal. Ca density profiles and concentrations of Mg, P, and Ca ions reveal extreme differences in the level and type of mineralization. Early mineralization in ovoids and tritors has very high levels of Mg, then a sudden increase in mineralization to a high total mineral content, whereas there is gradual change in trabecular dentine, remaining at a low level.Hypermineralized dentine fills the prepatterned ovoid, rod and tritor spaces, early at the aboral surface within the trabecular dentine. Deposition of the hypermineralized dentine (HD, proposed as new specific name, whitlockin replacing pleromin) is from surfaces that are lined with large specialized odontoblasts, (whitloblasts, instead of pleromoblasts) within cell body spaces connecting with extensive, ramifying tubules. Early mineralization occurs amongst this maze of tubules that penetrate far into the dentine, expanding into a mass of saccules and membranous bodies, dominating in the absence of other organic matrix. This early stage has hydroxyapatite, also significantly rich in Mg, initiated as a poorly crystalline phase. In the hypermineralized dentine, formation occurs as clusters of variably shaped crystals, arising from a sudden phase transition. CONCLUSIONS In the hypermineralized dentine, high MgO + CaO + P2O5 suggests that almost pure Mg containing tricalciumphosphate (MgTCP: (ß-Ca3(PO4)2) (whitlockite) is present, with little or no hydroxyapatite. Serial replacement of tritors and ovoids is suggested to occur within the dental plate, probably representing a relic of patterning, as classically found in elasmobranch dentitions.
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Affiliation(s)
- Moya Meredith Smith
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College London, London, SE1 9RT, UK
- Department of Earth Sciences, Natural History Museum London, London, SW7 5BD, UK
| | - Charlie Underwood
- Department of Earth and Planetary Sciences, Birkbeck, University of London, London, UK
| | - Tomasz Goral
- Department of Earth Sciences, Natural History Museum London, London, SW7 5BD, UK
- Current address: Center of New Technologies, University of Warsaw, Warsaw, Poland
| | - Christopher Healy
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College London, London, SE1 9RT, UK
| | - Zerina Johanson
- Department of Earth Sciences, Natural History Museum London, London, SW7 5BD, UK
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11
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Meredith Smith M, Underwood C, Clark B, Kriwet J, Johanson Z. Development and evolution of tooth renewal in neoselachian sharks as a model for transformation in chondrichthyan dentitions. J Anat 2018; 232:891-907. [PMID: 29504120 DOI: 10.1111/joa.12796] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2018] [Indexed: 12/01/2022] Open
Abstract
A defining feature of dentitions in modern sharks and rays is the regulated pattern order that generates multiple replacement teeth. These are arranged in labio-lingual files of replacement teeth that form in sequential time order both along the jaw and within successively initiated teeth in a deep dental lamina. Two distinct adult dentitions have been described: alternate, in which timing of new teeth alternates between two adjacent files, each erupting separately, and the other arranged as single files, where teeth of each file are timed to erupt together, in some taxa facilitating similarly timed teeth to join to form a cutting blade. Both are dependent on spatiotemporally regulated formation of new teeth. The adult Angel shark Squatina (Squalomorphii) exemplifies a single file dentition, but we obtained new data on the developmental order of teeth in the files of Squatina embryos, showing alternate timing of tooth initiation. This was based on micro-CT scans revealing that the earliest mineralised teeth at the jaw margin and their replacements in file pairs (odd and even jaw positions) alternate in their initiation timing. Along with Squatina, new observations from other squalomorphs such as Hexanchus and Chlamydoselachus, together with representatives of the sister group Galeomorphii, have established that the alternate tooth pattern (initiation time and replacement order) characterises the embryonic dentition of extant sharks; however, this can change in adults. These character states were plotted onto a recent phylogeny, demonstrating that the Squalomorphii show considerable plasticity of dental development. We propose a developmental-evolutionary model to allow change from the alternate to a single file alignment of replacement teeth. This establishes new dental morphologies in adult sharks from inherited alternate order.
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Affiliation(s)
- Moya Meredith Smith
- Tissue Engineering and Biophotonics, Dental Institute, King's College, London, UK.,Department of Earth Sciences, Natural History Museum, London, UK
| | - Charlie Underwood
- Department of Earth Sciences, Natural History Museum, London, UK.,Department of Earth and Planetary Sciences, Birkbeck, University of London, London, UK
| | - Brett Clark
- Department of Earth Sciences, Natural History Museum, London, UK
| | - Jürgen Kriwet
- Department of Palaeontology, University of Vienna, Vienna, Austria
| | - Zerina Johanson
- Department of Earth Sciences, Natural History Museum, London, UK
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12
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Aguilera O, Luz Z, Carrillo-Briceño JD, Kocsis L, Vennemann TW, de Toledo PM, Nogueira A, Amorim KB, Moraes-Santos H, Polck MR, Ruivo MDL, Linhares AP, Monteiro-Neto C. Neogene sharks and rays from the Brazilian 'Blue Amazon'. PLoS One 2017; 12:e0182740. [PMID: 28832664 PMCID: PMC5568136 DOI: 10.1371/journal.pone.0182740] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 07/24/2017] [Indexed: 11/18/2022] Open
Abstract
The lower Miocene Pirabas Formation in the North of Brazil was deposited under influence of the proto-Amazon River and is characterized by large changes in the ecological niches from the early Miocene onwards. To evaluate these ecological changes, the elasmobranch fauna of the fully marine, carbonate-rich beds was investigated. A diverse fauna with 24 taxa of sharks and rays was identified with the dominant groups being carcharhiniforms and myliobatiforms. This faunal composition is similar to other early Miocene assemblages from the proto-Carribbean bioprovince. However, the Pirabas Formation has unique features compared to the other localities; being the only Neogene fossil fish assemblage described from the Atlantic coast of Tropical Americas. Phosphate oxygen isotope composition of elasmobranch teeth served as proxies for paleotemperatures and paleoecology. The data are compatible with a predominantly tropical marine setting with recognized inshore and offshore habitats with some probable depth preferences (e.g., Aetomylaeus groups). Paleohabitat of taxa particularly found in the Neogene of the Americas (†Carcharhinus ackermannii, †Aetomylaeus cubensis) are estimated to have been principally coastal and shallow waters. Larger variation among the few analyzed modern selachians reflects a larger range for the isotopic composition of recent seawater compared to the early Miocene. This probably links to an increased influence of the Amazon River in the coastal regions during the Holocene.
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Affiliation(s)
- Orangel Aguilera
- Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brasil
- Instituto de Geociências, Universidade Federal do Pará, Belém, Pará, Brasil
| | - Zoneibe Luz
- Instituto de Geociências, Universidade Federal do Pará, Belém, Pará, Brasil
- * E-mail:
| | | | - László Kocsis
- Faculty of Science, Geology Group, University of Brunei Darussalam, Jalan Tungku, Gadong, Brunei Darussalam
| | - Torsten W. Vennemann
- Institut des Dynamiques de la Surface Terrestre, Université de Lausanne, Lausanne, Vaud, Switzerland
| | - Peter Mann de Toledo
- Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brasil
| | - Afonso Nogueira
- Instituto de Geociências, Universidade Federal do Pará, Belém, Pará, Brasil
| | - Kamilla Borges Amorim
- Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brasil
| | - Heloísa Moraes-Santos
- Coordenação de Ciências da Terra e Ecologia, Museu Paraense Emilio Goeldi, Belém, Pará, Brasil
| | - Marcia Reis Polck
- Departamento Nacional de Produção Mineral, Rio de Janeiro, Rio de Janeiro, Brasil
| | - Maria de Lourdes Ruivo
- Coordenação de Ciências da Terra e Ecologia, Museu Paraense Emilio Goeldi, Belém, Pará, Brasil
| | - Ana Paula Linhares
- Coordenação de Ciências da Terra e Ecologia, Museu Paraense Emilio Goeldi, Belém, Pará, Brasil
| | - Cassiano Monteiro-Neto
- Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brasil
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Manzanares E, Rasskin-Gutman D, Botella H. New insights into the enameloid microstructure of batoid fishes (Chondrichthyes). Zool J Linn Soc 2016. [DOI: 10.1111/zoj.12377] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Esther Manzanares
- Department of Geology; University of Valencia; C/Dr. Moliner 50 Burjassot Valencia E-46100 Spain
| | - Diego Rasskin-Gutman
- Institut Cavanilles de Biodiversitat I Biología Evolutiva; University of Valencia; C/Catedrático José Beltrán, 5, Paterna Valencia E-46980 Spain
| | - Héctor Botella
- Department of Geology; University of Valencia; C/Dr. Moliner 50 Burjassot Valencia E-46100 Spain
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