Cranial Morphology of the Carboniferous-Permian Tetrapod Brachydectes newberryi (Lepospondyli, Lysorophia): New Data from µCT

  title={Cranial Morphology of the Carboniferous-Permian Tetrapod Brachydectes newberryi (Lepospondyli, Lysorophia): New Data from µCT},
  author={Jason D. Pardo and Jason S. Anderson},
  journal={PLoS ONE},
Lysorophians are a group of early tetrapods with extremely elongate trunks, reduced limbs, and highly reduced skulls. Since the first discovery of this group, general similarities in outward appearance between lysorophians and some modern lissamphibian orders (specifically Urodela and Gymnophiona) have been recognized, and sometimes been the basis for hypotheses of lissamphibian origins. We studied the morphology of the skull, with particular emphasis on the neurocranium, of a partial growth… 

A review of the fossil record of caecilians (Lissamphibia: Gymnophionomorpha) with comments on its use to calibrate molecular timetrees

The caecilian fossil record is revisited, providing a brief description of all known extinct taxa described so far, along with general remarks about their impact on systematics, time range, and geographical distribution of the clade, as well as prospects for future research.

Infernovenator steenae, a new serpentine recumbirostran from the ‘Mazon Creek’ Lagerstätte further clarifies lysorophian origins

A new, virtually complete lysorophian genus and species is described, Infernovenator steenae gen. & sp.

New material of the ‘microsaur’ Llistrofus from the cave deposits of Richards Spur, Oklahoma and the paleoecology of the Hapsidopareiidae

It is proposed that Llistrofus may have been fossorial but was probably incapable of active burrowing in the fashion of recumbirostrans, which had more consolidated and reinforced skulls.

An earliest Triassic age for Tasmaniolimulus and comments on synchrotron tomography of Gondwanan horseshoe crabs

In revisiting these taxa, it is determined that, contrary to previous suggestion, T. patersoni arose after the Permian and the origin of over-developed genal spine structures within Austrolimulidae is exclusive to the Triassic.

Computed tomographic analysis of the cranium of the early Permian recumbirostran ‘microsaur’ Euryodus dalyae reveals new details of the braincase and mandible

Recumbirostran ‘microsaurs’ are a clade of Palaeozoic tetrapods that possess numerous morphological adaptations for fossorial ecologies. Re‐study of many ‘microsaurs’ using tomographic methods has

Postcranial anatomy of the ‘microsaur’ Carrolla craddocki from the Lower Permian of Texas

There is no longer any doubt regarding the association of the skull and postcranial remains of Carrolla craddocki, and an updated diagnosis for the taxon is provided.

Inner ear morphology of diadectomorphs and seymouriamorphs (Tetrapoda) uncovered by high‐resolution x‐ray microcomputed tomography, and the origin of the amniote crown group

The inner ear of seymouriamorphs foreshadows conditions of more derived groups, whereas that of diadectomorphs shows a mosaic of plesiomorphic and apomorphic traits, some of which are unambiguously amniote‐like, including a distinct and pyramid‐like cochlear recess.

A basal aïstopod from the earliest Pennsylvanian of Canada, and the antiquity of the first limbless tetrapod lineage

The anatomy of A. longidentatum corroborates recent phylogenetic work which has placed the origin of aïstopods within the Devonian fin-to-limb transition but preserves a mosaic of characteristics suggesting an even earlier divergence, and suggests that Joggins may preserve a more typical Carboniferous fauna than previously thought.

A redescription of Orovenator mayorum (Sauropsida, Diapsida) using high‐resolution μCT, and the consequences for early amniote phylogeny

The earliest known neodiapsid Orovenator mayorum from the lower Permian of Oklahoma is redescribed using high‐resolution μCT, revealing remarkable details of the skull anatomy and prompting questions about relationships among early amniotes.

Morphology of the temporal skull region in tetrapods: research history, functional explanations, and a new comprehensive classification scheme

  • Pascal AbelI. Werneburg
  • Environmental Science, Biology
    Biological reviews of the Cambridge Philosophical Society
  • 2021
A novel comprehensive classification scheme for the various temporal morphotypes in all Tetrapoda that is independent of phylogeny and previous terminology is introduced that may facilitate morphological comparisons in future studies.



Cranial Morphology of the Brachystelechid ‘Microsaur’ Quasicaecilia texana Carroll Provides New Insights into the Diversity and Evolution of Braincase Morphology in Recumbirostran ‘Microsaurs’

The organization of the skull roof and braincase of Quasicaecilia is found to be more in line with that of other recumbirostrans than previously described, despite differences in overall shape, and the importance of future attention to the role of the cervical musculature is underscored.

A redescription of Carrolla craddocki (Lepospondyli: Brachystelechidae) based on high‐resolution CT, and the impacts of miniaturization and fossoriality on morphology

The results suggest brachystelechid cranial morphology is strongly influenced by miniaturization (enlarged sensory organs, anterior placement of the jaw articulation, and combination of both reduced‐ and hyper‐ossifications) and burrowing habits and future efforts should continue to focus on fine details of anatomy minimally affected by these influences to contribute to the resolution of the question of the origin of caecilians.

The interrelationships of Devonian lungfishes (Sarcopterygii: Dipnoi) as inferred from neurocranial evidence and new data from the genus Soederberghia Lehman, 1959

This study indicates that Griphognathus is probably paraphyletic, it nevertheless supports a close relationship between the nominal species of this genus and Soederberghia, and fails to find support for the monophyly of either.


An anatomical study of Microbrachis reveals inaccuracies in previous studies, especially in the palate and cranial proportions, which corroborates previous suggestions that lissamphibians are part of a clade that includes the taxa classically referred to as “lepospondyls,” and that seymouriamorphs and temnospONDyls are not part of Tetrapoda.

Nannaroter mckinziei, a New Ostodolepid ‘Microsaur’ (Tetrapoda, Lepospondyli, Recumbirostra) from the Early Permian of Richards Spur (Ft. Sill), Oklahoma

Despite its small size, Nannaroter has a massively ossified skull with deeply interlocking sutures designed to tightly resist anteroposteriorly directed forces, which will explore adaptations in amphibians to a fossorial lifestyle.

Functional morphology of the skull in Lysorophus: a snake-like Paleozoic amphibian (Lepospondyli)

Modifications in the skull of Lysorophus from a more primitive tetrapod condition seem associated with burrowng in a soft substratum rather than with kinesis per se.

Cranial Morphology of Recumbirostrans (Lepospondyli) from the Permian of Kansas and Nebraska, and Early Morphological Evolution Inferred by Micro-Computed Tomography

ABSTRACT ‘Microsaurs’ (Lepospondyli) were a group of tetrapods whose fossil record spanned the Mississippian—Early Permian, and have sometimes been implicated in the origins of lissamphibians

The Braincase of Eocaecilia micropodia (Lissamphibia, Gymnophiona) and the Origin of Caecilians

The braincase of E. micropodia was examined via micro-computed tomography and Ancestral character state reconstruction confirms the braincase to be largely representative of the plesiomorphic condition of extant caecilians.


Details of Cranial anatomy contradict a previous model of cranial kinesis by severely limiting the skull's potential mobility and three species are recognised within the family Phlegethontiidae.

Cranial anatomy of the stem salamander Kokartus honorarius (Amphibia: Caudata) from the Middle Jurassic of Kyrgyzstan

The morphological analysis of Kokartus supports the current phylogenetic hypothesis that Permian amphibamids (including branchiosaurids) are the closest relatives of salamanders amongst known non-lissamphibian temnospondyls.