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

  title={Cranial Morphology of Recumbirostrans (Lepospondyli) from the Permian of Kansas and Nebraska, and Early Morphological Evolution Inferred by Micro-Computed Tomography},
  author={Adam K. Huttenlocker and Jason D. Pardo and Bryan J. Small and Jason S. Anderson},
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 (especially the fossorial caecilians). Although common in the well-sampled Permian deposits of Texas and Oklahoma, little is known of conservative recumbirostran ‘microsaurs’ from more northerly localities (Kansas/Nebraska). Data on a new, well-preserved recumbirostran, Huskerpeton englehorni, gen. et sp… 
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.
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
Cranial Morphology of the Carboniferous-Permian Tetrapod Brachydectes newberryi (Lepospondyli, Lysorophia): New Data from µCT
The morphology of the skull of a partial growth series of the lysorophian Brachydectes newberryi is studied using x-ray micro-computed tomography and reveals similarities between the braincase of BrachydECTes and brachystelechid recumbirostrans, corroborating prior work suggesting a close relationship between these taxa.
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.
Neurocranial Anatomy of Seymouria from Richards Spur, Oklahoma
ABSTRACT Seymouriamorphs are a group of Permo-Carboniferous tetrapods with both terrestrial and aquatic members. Since their initial discovery, they have been proposed as phylogenetic intermediates
Micro-CT Study of Rhynchonkos stovalli (Lepospondyli, Recumbirostra), with Description of Two New Genera
The morphology of the holotype and three specimens previously attributed to R. stovalli are studied with the use of micro-computed x-ray tomography, resulting in proposed similarities that are more ambiguous than previous descriptions suggest.
Revised Description of the Early Permian Recumbirostran “Microsaur” Nannaroter mckinziei Based on New Fossil Material and Computed Tomographic Data
A new partial skull of the recumbirostran “microsaur” Nannaroter mckinziei is presented and an updated description of the taxon is provided, which provides novel information regarding several regions that could not be examined previously due to either being absent in the holotype or difficult to access.
Joermungandr bolti, an exceptionally preserved ‘microsaur’ from the Mazon Creek Lagerstätte reveals patterns of integumentary evolution in Recumbirostra
The Carboniferous Pennsylvanian-aged (309–307 Ma) Mazon Creek Lagerstätte produces some of the earliest fossils of major Palaeozoic tetrapod lineages. Recently, several new tetrapod specimens
Reassessment of historic ‘microsaurs’ from Joggins, Nova Scotia, reveals hidden diversity in the earliest amniote ecosystem
‘Microsaurs’ are traditionally considered to be lepospondyl non‐amniotes, but recent analyses have recovered a subset of ‘microsaurs’, the fossorially adapted Recumbirostra, within Amniota. This
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.


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.
An Ostodolepid ‘Microsaur’ (Lepospondyli) from the Lower Permian Tambach Formation of Central Germany
ABSTRACT Tambaroter carrolli is a new genus and species of medium-sized ostodolepid ‘microsaur’ from the Lower Permian Tambach Formation, lowermost formational unit of the Upper Rotliegend,
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.
A new microsaur (Tetrapoda: Lepospondyli) from the Lower Permian of Richards Spur (Fort Sill), Oklahoma
Bolterpeton carrolli n.gen. n.sp. is described from the Lower Permian fissure-fill deposits of Richards Spur, Oklahoma. Bolterpeton is united with the gymnarthrid microsaur Cardiocephalus by having
A Redescription Of Acroplous vorax (Temnospondyli: Dvinosauria) Based On New Specimens From the Early Permian Of Nebraska and Kansas, U.S.A.
A cladistic analysis of 87 characters and 12 temnospondyl taxa indicates that the Eobrachyopidae (Acroplous and Isodectes) may be a paraphyletic group, with IsodECTes filling a more basal position within the Dvinosauroidea.
A new genus and species of amphibamid dissorophoid, Plemmyradytes shintoni, is described from the lower half of the Permian-aged Eskridge Formation near Humboldt, Nebraska, and the demonstration of evolutionary trends within the family based on the new data allows a comparison of competing phylogenetic hypotheses.
A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders
The discovery of an amphibamid temnospondyl from the Early Permian of Texas that bridges the gap between other Palaeozoic amphibians and the earliest known salientians and caudatans from the Mesozoic is reported.
Abstract Burrows of the lysorophid amphibian Brachydectes elongatus occur in deposits interpreted as ephemeral ponds within the Lower Permian Speiser Shale of eastern Kansas. The burrows of B.
The phylogenetic trunk: maximal inclusion of taxa with missing data in an analysis of the lepospondyli (Vertebrata, Tetrapoda).
The phylogenetic trunk approach is proposed to allow optimization of taxonomic inclusion and tree stability and finds a single most-parsimonious tree, or trunk, after the removal of one taxon identified as being problematic.