New material of the choristodere<i>Lazarussuchus</i>(Diapsida, Choristodera) from the Paleocene of France

Matsumoto, Ryoko; Buffetaut, Éric; Escuillié, François; Hervet, Sophie; Evans, SE

doi:10.1080/02724634.2012.716274

Cited by 28 publications

(52 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…, ) are from the Early Cretaceous of Asia (China and Japan), whereas the European Lazarussuchus ( L. inexpectatus ; Hecht, ; L. dvoraki ; Evans & Klembara, ) is recorded from the Late Paleocene (France; Matsumoto et al. ) to Early Miocene (France, Czech Republic, Germany; Hecht, ; Evans & Klembara, ; Böhme, ). Neochoristodera (short‐necked longirostrine type) is comprised of four genera of similar morphology – the Early Cretaceous Tchoiria ( T. namsarai ; T. klauseni ; Efimov, ; Ksepka et al.…”

Section: Introductionmentioning

confidence: 99%

Morphology and function of the palatal dentition in Choristodera

Matsumoto

Evans

2015

Journal of Anatomy

Self Cite

View full text Add to dashboard Cite

Choristoderes are a group of extinct freshwater reptiles that were distributed throughout Laurasia from the Middle Jurassic to the Miocene. They are inferred to have had a lifestyle similar to that of extant gavialid crocodiles, but they differed from crocodiles in retaining an extensive palatal dentition. All choristoderes had teeth on the vomers, palatines and pterygoids, and teeth are rarely present on the parasphenoid. Palatal teeth are conical, as in the marginal dentition, and form longitudinal and transverse rows. Detailed examination of different genera shows that the orientation of the palatal tooth crowns changes with their position on the palate, supporting the view that they are involved in intra-oral food transportation, presumably in combination with a fleshy tongue. Moreover, observed variation in palatal tooth shape and the width of palatal tooth batteries may provide additional clues about diet. The European Simoedosaurus lemoinei has sharper palatal teeth than its North American counterpart, S. dakotensis, suggesting a preference for softer prey - a conclusion consistent with the more gracile teeth and narrower snout.

show abstract

Section: Introductionmentioning

confidence: 99%

Morphology and function of the palatal dentition in Choristodera

Matsumoto

Evans

2015

Journal of Anatomy

Self Cite

View full text Add to dashboard Cite

show abstract

“…The internarial element is unique to Champsosaurus and is a diagnostic feature of the genus (Gao & Fox, ; Matsumoto et al ). The internarial was described as a neomorphic ossification by Russell (), Romer () and Erickson (), and is possibly derived from the cartilaginous internarial septum (Russell, ).…”

Section: Discussionmentioning

confidence: 99%

“…The variability in the ossification of this region may correlate with the distribution of bite force across the chondrocranium (Evans, 2008;Jones et al 2017). The internarial element is unique to Champsosaurus and is a diagnostic feature of the genus (Gao & Fox, 1998;Matsumoto et al 2013). The internarial was described as a neomorphic ossification by Russell (1956), Romer (1956) and Erickson (1972), and is possibly derived from the cartilaginous internarial septum (Russell, 1956).…”

Section: Conservation Of the Braincase Among Amniotes And Its Implicamentioning

confidence: 99%

Computed tomography analysis of the cranium of Champsosaurus lindoei and implications for the choristoderan neomorphic ossification

et al. 2020

View full text Add to dashboard Cite

Choristoderes are extinct neodiapsid reptiles that are well known for their unusual cranial anatomy, possessing an elongated snout and expanded temporal arches. Although choristodere skulls are well described externally, their internal anatomy remains unknown. An internal description was needed to shed light on peculiarities of the choristodere skull, such as paired gaps on the ventral surface of the skull that may pertain to the fenestra ovalis, and a putative neomorphic ossification in the lateral wall of the braincase. Our goals were: (i) to describe the cranial elements of Champsosaurus lindoei in three dimensions; (ii) to describe paired gaps on the ventral surface of the skull to determine if these are indeed the fenestrae ovales; (iii) to illustrate the morphology of the putative neomorphic bone; and (iv) to consider the possible developmental and functional origins of the neomorph. We examined the cranial anatomy of the choristodere Champsosaurus lindoei (CMN 8920) using high‐resolution micro‐computed tomography scanning. We found that the paired gaps on the ventral surface of the skull do pertain to the fenestrae ovales, an unusual arrangement that may be convergent with some plesiosaurs, some aistopods, and some urodeles. The implications of this morphology in Champsosaurus are unknown and will be the subject of future work. We found that the neomorphic bone is a distinct ossification, but is not part of the wall of the brain cavity or the auditory capsule. Variation in the developmental pathways of cranial bones in living amniotes was surveyed to determine how the neomorphic bone may have developed. We found that the chondrocranium and splanchnocranium show little to no variation across amniotes, and the neomorphic bone is therefore most likely to have developed from the dermatocranium; however, the stapes is a pre‐existing cranial element that is undescribed in choristoderes and may be homologous with the neomorphic bone. If the neomorphic bone is not homologous with the stapes, the neomorph likely developed from the dermatocranium through incomplete fusion of ossification centres from a pre‐existing bone, most likely the parietal. Based on the apparent morphology of the neomorph in Coeruleodraco, the neomorph was probably too small to play a significant structural role in the skull of early choristoderes and it may have arisen through non‐adaptive means. In neochoristoderes, such as Champsosaurus, the neomorph was likely recruited to support the expanded temporal arches.

show abstract

“…The earliest representative of the choristoderes is Cteniogenys from the Bathonian of England and Scotland (Evans, 1990;Evans et al, 2006) and the fossil from GEA 2 if its allocation is confirmed. In addition, the fossil from GEA 2 would be the first choristodere recovered from a Gondwanan continent (Matsumoto et al, 2013).…”

Section: Systematic Paleontology Of the Guelb El Ahmar Faunamentioning

confidence: 99%

Guelb el Ahmar (Bathonian, Anoual Syncline, eastern Morocco): First continental flora and fauna including mammals from the Middle Jurassic of Africa

et al. 2016

View full text Add to dashboard Cite

We report the discovery in Mesozoic continental "red beds" of Anoual Syncline, Morocco, of the new Guelb el Ahmar (GEA) fossiliferous sites in the Bathonian Anoual Formation. They produced one of the richest continental biotic assemblages from the Jurassic of Gondwana, including plants, invertebrates and vertebrates. Both the sedimentological facies and the biotic assemblage indicate a lacustrine depositional environment. The flora is represented by tree trunks (three families), pollen (13 species, five major clades) and charophytes. It suggests local forests and humid (non-arid) conditions. The vertebrate fauna is dominated by microvertebrates recovered by screening-washing. It is rich and diverse, with at least 29 species of all major groups (osteichthyans, lissamphibians, chelonians, diapsids, mammals), except chondrichthyans. It includes the first mammals discovered in the Middle Jurassic of Arabo-Africa. The GEA sites yielded some of the earliest known representatives of osteoglossiform fishes, albanerpetontid and caudate amphibians, squamates (scincomorphans, anguimorphan), cladotherian mammals, and likely choristoderes. The choristoderes, if confirmed, are the first found in Gondwana, the albanerpetontid and caudatan amphibians are among the very few known in Gondwana, and the anguimorph lizard is the first known from the Mesozoic of Gondwana. Mammals (Amphitheriida, cf. Dryolestida) remain poorly known, but are the earliest cladotherians known in Gondwana. The GEA biotic assemblage is characterized by the presence of Pangean and Laurasian (especially European) taxa, and quasi absence of Gondwanan taxa. The paleobiogeographical analysis suggests either a major fossil bias in Gondwana during the Middle Jurassic, and an overall vicariant Pangean context for the GEA assemblage, or alternatively, noticeable Laurasian (European) affinities and North-South dispersals. The close resemblance between the Bathonian faunas of GEA and Britain is remarkable, even in a Pangean context. The similarity between the local Anoual Syncline Guelb el Ahmar and Ksar Metlili faunas raises questions on the ?Berriasian age of the latter.

show abstract

New material of the choristodereLazarussuchus(Diapsida, Choristodera) from the Paleocene of France

Cited by 28 publications

References 40 publications

Morphology and function of the palatal dentition in Choristodera

Morphology and function of the palatal dentition in Choristodera

Computed tomography analysis of the cranium of Champsosaurus lindoei and implications for the choristoderan neomorphic ossification

Guelb el Ahmar (Bathonian, Anoual Syncline, eastern Morocco): First continental flora and fauna including mammals from the Middle Jurassic of Africa

Contact Info

Product

Resources

About