Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-20T11:47:30.409Z Has data issue: false hasContentIssue false

A Crassigyrinus-like jaw from the Tournaisian (Early Mississippian) of Scotland

Published online by Cambridge University Press:  03 August 2018

Jennifer A. Clack*
Affiliation:
University Museum of Zoology, Downing Street, Cambridge CB2 3EJ, UK. Email: [email protected]
Laura B. Porro*
Affiliation:
Structure and Motion Laboratory, Royal Veterinary College, Hawkshead Lane, Hatfield AL9 7TA, UK. School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK.
Carys E. Bennett*
Affiliation:
School of Geography, Geology and the Environment, University of Leicester, University Road, Leicester LE1 7RH, UK.
*
*Corresponding authors

Abstract

The early tetrapod Crassigyrinus scoticus was a large aquatic predator from the mid Carboniferous (late Viséan or early Serpukovian) of Scotland, around 330 My in age. There are five main specimens with cranial remains: an articulated skeleton; two incomplete skulls; and two lower jaws. Crassigyrinus retains several apparently primitive features of the palatal dentition and lower jaw, and its phylogenetic position is disputed. A partial lower jaw resembling that of Crassigyrinus was discovered at Burnmouth in the Borders region of Scotland. The horizon in which it was found is dated as late Tournaisian, CM palynozone, around 350 My in age. Though it lacks dentition, the jaw preserves much of the postsplenial, angular and surangular, whose appearance externally and internally is almost identical to that of C. scoticus. Internally, the jaw shows a similarly limited extent of the suturing between the splenial series and the prearticular, a primitive condition. Externally, the type and distribution of dermal ornamentation closely matches that of C. scoticus, as does the deeply excavated and marginally positioned lateral line groove. As well as external and internal features, all specimens of C. scoticus are of similar skull size, though the Burnmouth jaw is somewhat smaller. If correctly attributable to Crassigyrinus, this specimen extends the existence of the genus by approximately 20 million years towards the base of the Carboniferous.

Type
Articles
Copyright
Copyright © The Royal Society of Edinburgh 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

6. References

Ahlberg, P. E. 1991. A re-examination of sarcopterygian interrelationships, with special reference to the Porolepiformes. Zoological Journal of the Linnean Society of London 103, 241287.Google Scholar
Ahlberg, P. E. & Clack, J. A. 1998. Lower jaws, lower tetrapods – a review based on the Devonian genus Acanthostega. Transactions of the Royal Society of Edinburgh: Earth Sciences 89, 1146.Google Scholar
Anderson, J. S., Smithson, T. R., Mansky, C., Meyer, T., Carroll, R. L. & Clack, J. A. 2015. A diverse tetrapod fauna at the base of Romer's Gap. PloS ONE 10(4), e0125446. doi:10.1371/journal.pone.0125446Google Scholar
Bolt, J. R. & Lombard, R. E. 2001. The mandible of the primitive tetrapod Greererpeton, and the early evolution of the tetrapod lower jaw. Journal of Paleontology 75, 1016–42.Google Scholar
Bolt, J. R. & Lombard, R. E. 2006. Sigournea multidentata, a new stem tetrapod from the Upper Mississippian of Iowa, USA. Journal of Paleontology 80, 717725.Google Scholar
Cavin, L., Suteethorn, V., Buffetaut, E. & Tong, H. 2007. A new Thai Mesozoic lungfish (Sarcopterygii, Dipnoi) with an insight into post-Palaeozoic dipnoan evolution. Zoological Journal of the Linnean Society 149, 141177.Google Scholar
Clack, J. A. 1996. The palate of Crassigyrinus scoticus from the Viséan of Scotland. In Milner, A. R. (ed.) Studies on Carboniferous and Permian Vertebrates. Special Papers in Palaeontology 52, 5564.Google Scholar
Clack, J. A. 1998. The Scottish Carboniferous tetrapod Crassigyrinus scoticus (Lydekker) – cranial anatomy and relationships. Transactions of the Royal Society of Edinburgh, Earth Sciences 88(for 1997), 127142.Google Scholar
Clack, J. A. 2002. An early tetrapod from Romer's Gap. Nature 418, 7276.Google Scholar
Clack, J. A., Ahlberg, P. E., Blom, H. & Finney, S. M. 2012. A new genus of Devonian tetrapod from East Greenland, with new information on the lower jaw of Ichthyostega. Palaeontology 55, 7386.Google Scholar
Clack, J. A., Bennett, C. E., Carpenter, D. K., Davies, S. J., Fraser, N. C., Kearsey, T. I., Marshall, J. E. A., Millward, D., Otoo, B. K. A., Reeves, E. J., Ross, A. J., Ruta, M., Smithson, K. Z., Smithson, T. R. & Walsh, S. A. 2016. Phylogenetic and environmental diversity revealed for Tournaisian tetrapods. Nature Ecology and Evolution 1. doi: 10.1038/s41559-016-0002Google Scholar
Clack, J. A. & Carroll, R. L. 2000. Early Carboniferous tetrapods. In Heatwole, H. & Carroll, R. L. (eds) Amphibian Biology, Volume 4 Palaeontology: The Evolutionary History of Amphibians, 10301043. Chipping Norton, NSW, Australia: Surrey Beatty.Google Scholar
Clack, J. A. & Finney, S. M. 2005. Pederpes finneyae, an articulated tetrapod from the Tournaisian of western Scotland. Journal of Systematic Palaeontology 2, 311346.Google Scholar
Gradstein, F. M., Ogg, J. G., Schmitz, M. D. & Ogg, G. M. (eds) 2012. The Geological Time Scale 2012. Oxford: Elsevier.Google Scholar
Huene, F. V. 1948. Short review of the lower tetrapods. Royal Society of South Africa Special Publications. Robert Broom Commemorative Volume 65106.Google Scholar
Huxley, T. H. 1880. On the applications of the laws of evolution to the arrangment of the Vertebrata and more particularly of the Mammalia. Proceedings of the Zoological Society of London 1880, 649662.Google Scholar
Kemp, A. & Molnar, R. E. 1981. Neoceratodus forsteri from the Lower Cretaceous of New South Wales, Australia. Journal of Paleontology 55, 211217.Google Scholar
Klembara, J., Clack, J. A., Milner, A. R. & Ruta, M. 2014. Cranial anatomy, ontogeny and relationships of the Late Carboniferous tetrapod Gephyrostegus bohemicus Jaekel, 1902. Journal of Vertebrate Paleontology 34, 774792.Google Scholar
Laurin, M. 2004. The evolution of body size, Cope's rule and the origin of amniotes. Systematic Biology 53, 594622.Google Scholar
Lombard, R. E. & Bolt, J. R. 2006. The mandible of Whatcheeria deltae, an early tetrapod from the Late Mississippian of Iowa. In Carrano, M. T., Gaudin, T. J., Blob, R. W. & Wible, J. R. (eds) Amniote Paleobiology: Perspectives on the Evolution of Mammals, Birds, and Reptiles, 2152. Chicago: Chicago University Press. 448 pp.Google Scholar
Panchen, A. L. 1973. On Crassigyrinus scoticus Watson, a primitive amphibian from the Lower Carboniferous of Scotland. Palaeontology 16, 179193.Google Scholar
Panchen, A. L. 1985. On the amphibian Crassigyrinus scoticus Watson from the Carboniferous of Scotland. Philosophical Transactions of the Royal Society of London. Series B 309, 461568.Google Scholar
Romer, A. S. 1955. Herpetichthyes, Amphibioidea, Choanichthyes or Sarcopterygii? Nature 176, 126.Google Scholar
Ruta, M. & Clack, J. A. 2006. A review of Silvanerpeton miripedes, a stem amniote from the Lower Carboniferous of East Kirkton, West Lothian, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 97, 3163.Google Scholar
Sallan, L. C. & Coates, M. I. 2010. End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates. Proceedings of the National Academy of Sciences 107, 1013110135.Google Scholar
Scrutton, C. & Turner, B. 1995. The Geology of Eyemouth and Burnmouth. In Scrutton, C. (ed.) Northumbrian rocks and landscape, a field guide, 3141. York, UK: Yorkshire Geological Society. 216 pp.Google Scholar
Smithson, T. R. 1982. The cranial morphology of Greererpeton burkemorani (Amphibia: Temnospondyli). Zoological Journal of the Linnean Society of London 76, 2990.Google Scholar
Smithson, T. R., Wood, S. P., Marshall, J. E. A. & Clack, J. A. 2012. Earliest Carboniferous tetrapod and arthropod faunas from Scotland populate Romer's Gap. Proceedings of the National Academy of Sciences 109, 4532–37.Google Scholar
Sookias, R. B., Böhmer, C. & Clack, J. A. 2014. Redescription and phylogenetic analysis of the mandible of an enigmatic Late Carboniferous tetrapod from Nova Scotia, and the lability of Meckelian ossification. PLOS ONE 9(10), e109717.Google Scholar
Warren, A. A. 2007. New data on Ossinodus pueri, a stem tetrapod from the Early Carboniferous of Australia. Journal of Vertebrate Paleontology 27, 850862.Google Scholar
Watson, D. M. S. 1929. The Carboniferous Amphibia of Scotland. Palaontologica Hungarica 1, 219252.Google Scholar