The parabasisphenoid complex in Mesozoic turtles and the evolution of the testudinate basicranium

Sterli, Juliana; Müller, Johannes; Anquetin, Jérémy; Hilger, André

doi:10.1139/e10-061

Cited by 52 publications

(38 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The external pterygoid process is clearly developed, has a small posterior projection, and a small, but distinct vertical plate. The pterygoid has a short, but clear sutural contact with the parabasisphenoid (sensu [36]) along the midline. The interpterygoid vacuity is therefore closed and the palatine artery enters the skull through a distinct foramen posterius canalis carotici palatinum formed by the pterygoid and the basisphenoid.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles

et al. 2016

View full text Add to dashboard Cite

BackgroundTurtles (Testudinata) are a successful lineage of vertebrates with about 350 extant species that inhabit all major oceans and landmasses with tropical to temperate climates. The rich fossil record of turtles documents the adaptation of various sub-lineages to a broad range of habitat preferences, but a synthetic biogeographic model is still lacking for the group.ResultsWe herein describe a new species of fossil turtle from the Late Jurassic of Xinjiang, China, Sichuanchelys palatodentata sp. nov., that is highly unusual by plesiomorphically exhibiting palatal teeth. Phylogenetic analysis places the Late Jurassic Sichuanchelys palatodentata in a clade with the Late Cretaceous Mongolochelys efremovi outside crown group Testudines thereby establishing the prolonged presence of a previously unrecognized clade of turtles in Asia, herein named Sichuanchelyidae. In contrast to previous hypotheses, M. efremovi and Kallokibotion bajazidi are not found within Meiolaniformes, a clade that is here reinterpreted as being restricted to Gondwana.ConclusionsA revision of the global distribution of fossil and recent turtle reveals that the three primary lineages of derived, aquatic turtles, including the crown, Paracryptodira, Pan-Pleurodira, and Pan-Cryptodira can be traced back to the Middle Jurassic of Euramerica, Gondwana, and Asia, respectively, which resulted from the primary break up of Pangaea at that time. The two primary lineages of Pleurodira, Pan-Pelomedusoides and Pan-Chelidae, can similarly be traced back to the Cretaceous of northern and southern Gondwana, respectively, which were separated from one another by a large desert zone during that time. The primary divergence of crown turtles was therefore driven by vicariance to the primary freshwater aquatic habitat of these lineages. The temporally persistent lineages of basal turtles, Helochelydridae, Meiolaniformes, Sichuanchelyidae, can similarly be traced back to the Late Mesozoic of Euramerica, southern Gondwana, and Asia. Given the ambiguous phylogenetic relationships of these three lineages, it is unclear if their diversification was driven by vicariance as well, or if they display a vicariance-like pattern. The clean, primary signal apparent among early turtles is secondarily obliterated throughout the Late Cretaceous to Recent by extensive dispersal of continental turtles and by multiple invasions of marine habitats.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0762-5) contains supplementary material, which is available to authorized users.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The parabasisphenoid consists of the basisphenoid and the parasphenoid [36]. Its dual composition is best revealed at its posterior end, where it is possible to discern the parasphenoid as a thin lamina that only partially overlaps the basisphenoid in this region (Fig.…”

Section: Resultsmentioning

confidence: 99%

A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles

et al. 2016

View full text Add to dashboard Cite

show abstract

“…However, the stapes of P. quenstedti was much stouter than that of crown-turtles (Figures 4D,E), and possibly articulated with the quadrate (Gaffney, 1990), suggesting that it was not as effective as the thin vibratory element characteristic of extant amniotes with tympanic hearing, including modern turtles (Baird, 1970;Clack, 1997). As proposed by Clack (1997) for diapsids, elongation of the paraoccipital process of the opisthotic and its tight suturing to the squamosal, which occurred in the group including all testudinates but Proganochelys quenstedti (Sterli et al, 2010), may have completely released the stapes from its ancestral structural function (connecting the quadrate to other elements of the braincase) during turtle evolution.…”

Section: Sensory Capabilities Of Proganochelysmentioning

confidence: 97%

Sensory Evolution and Ecology of Early Turtles Revealed by Digital Endocranial Reconstructions

2018

View full text Add to dashboard Cite

In the past few years, new fossil finds and novel methodological approaches have prompted intensive discussions about the phylogenetic affinities of turtles and rekindled the debate on their ecological origin, with very distinct scenarios, such as fossoriality and aquatic habitat occupation, proposed for the earliest stem-turtles. While research has focused largely on the origin of the anapsid skull and unique postcranial anatomy, little is known about the endocranial anatomy of turtles. Here, we provide 3D digital reconstructions and comparative descriptions of the brain, nasal cavity, neurovascular structures and endosseous labyrinth of Proganochelys quenstedti, one of the earliest stem-turtles, as well as other turtle taxa. Our results demonstrate that P. quenstedti retained a simple tube-like brain morphology with poorly differentiated regions and mediocre hearing and vision, but a well-developed olfactory sense. Endocast shape analysis indicates that an increase in size and regionalization of the brain took place in the course of turtle evolution, achieving an endocast diversity comparable to other amniote groups. Based on the new evidence presented herein, we further conclude that P. quenstedti was a highly terrestrial, but most likely not fossorial, taxon.

show abstract

“…sp., has previously been shown to exhibit a pair of lateral processes that were homologized with the basipterygoid process of basal amniotes [15,17]. However, the homology of these structures is controversial in the literature [18-20] and a comprehensive assessment of this issue is still outstanding. We here identify similar basisphenoid processes in a broad range of extinct turtles and conclude that their presence has been overlooked in the Mesozoic turtle literature during the last forty years.…”

Section: Introductionmentioning

confidence: 99%

A new xinjiangchelyid turtle from the Middle Jurassic of Xinjiang, China and the evolution of the basipterygoid process in Mesozoic turtles

et al. 2013

View full text Add to dashboard Cite

BackgroundMost turtles from the Middle and Late Jurassic of Asia are referred to the newly defined clade Xinjiangchelyidae, a group of mostly shell-based, generalized, small to mid-sized aquatic froms that are widely considered to represent the stem lineage of Cryptodira. Xinjiangchelyids provide us with great insights into the plesiomorphic anatomy of crown-cryptodires, the most diverse group of living turtles, and they are particularly relevant for understanding the origin and early divergence of the primary clades of extant turtles.ResultsExceptionally complete new xinjiangchelyid material from the ?Qigu Formation of the Turpan Basin (Xinjiang Autonomous Province, China) provides new insights into the anatomy of this group and is assigned to Xinjiangchelys wusu n. sp. A phylogenetic analysis places Xinjiangchelys wusu n. sp. in a monophyletic polytomy with other xinjiangchelyids, including Xinjiangchelys junggarensis, X. radiplicatoides, X. levensis and X. latiens. However, the analysis supports the unorthodox, though tentative placement of xinjiangchelyids and sinemydids outside of crown-group Testudines. A particularly interesting new observation is that the skull of this xinjiangchelyid retains such primitive features as a reduced interpterygoid vacuity and basipterygoid processes.ConclusionsThe homology of basipterygoid processes is confidently demonstrated based on a comprehensive review of the basicranial anatomy of Mesozoic turtles and a new nomenclatural system is introduced for the carotid canal system of turtles. The loss of the basipterygoid process and the bony enclosure of the carotid circulation system occurred a number of times independently during turtle evolution suggesting that the reinforcement of the basicranial region was essential for developing a rigid skull, thus paralleling the evolution of other amniote groups with massive skulls.

show abstract

The parabasisphenoid complex in Mesozoic turtles and the evolution of the testudinate basicranium

Cited by 52 publications

References 13 publications

A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles

A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles

Sensory Evolution and Ecology of Early Turtles Revealed by Digital Endocranial Reconstructions

A new xinjiangchelyid turtle from the Middle Jurassic of Xinjiang, China and the evolution of the basipterygoid process in Mesozoic turtles

Contact Info

Product

Resources

About