Carbonodraco lundi gen et sp. Nov., the oldest parareptile, from Linton, Ohio, and new insights into the early radiation of reptiles

Redescription of the holotype specimen of Cephalerpeton ventriarmatum Moodie, 1912, from the Middle Pennsylvanian (Moscovian) Francis Creek Shale of Mazon Creek, Illinois, confirms that it is a basal eureptile with close postcranial similarities to other protorothyridids, such as Anthracodromeus and Paleothyris. The skull is long and lightly built, with large orbits and a dorsoventrally short mandible similar to most basal eureptiles. Two specimens referred previously to Cephalerpeton cf. C. ventriarmatum from the approximately coeval Linton, Ohio, locality differ significantly from the holotype in cranial and mandibular proportions and tooth morphology. This material and an additional Linton specimen compare favourably to ‘short-faced’ parareptiles, such as Colobomycter and Acleistorhinus, and justify recognition of an acleistorhinid parareptile in the Linton assemblage. The new binomen is thus the oldest known parareptile

Antiquity of “Sail-Backed” Neural Spine Hyper-Elongation in Mammal Forerunners

Neural spine hyper-elongation in tetrapods is a unique morphological adaptation that creates a dorsal sail. While this extreme morphology has appeared several times in the evolutionary history of tetrapods, it was first experimented with by the non-mammalian synapsid paraphyletic group known as “Pelycosaurs,” famously represente

Diabloroter bolti, a short-bodied recumbirostran 'microsaur' from the Francis Creek Shale, Mazon Creek, Illinois

The Carboniferous (Pennsylvanian; 309-307 Mya) 'Mazon Creek' Lagerstätte produces some of the earliest tetrapod fossils of major Palaeozoic lineages. Previously, the Mazon Creek record of 'microsaurs' was known from a single specimen. However, the lack of key anatomy, such as the skull, precluded a confident taxonomic assignment, thus only a suggested affinity to the microbrachimorph 'microsaur' Hyloplesion was determined. Recently several new tetrapod specimens collected from Mazon Creek have come to light, of which some have recumbirostran 'microsaur' affinity. Here we describe a new genus and species of short-bodied recumbirostran, Diabloroter bolti, on the basis of a unique combination of autapomorphies. Both parsimony and Bayesian phylogenetic methods recover the new taxon in the Brachystelechidae clade, as sister to a clade including Carrolla and Batropetes. We determine Diabloroter to be the earliest known member of Brachytelechidae and thus establishing a Carboniferous origin of the family. We also provide an updated diagnosis for Brachystelechidae. Finally, we comment on the evolutionary trends in the clade, including dental adaptations for a proposed algivorous diet in derived clade members

Varanopid from the Carboniferous of Nova Scotia reveals evidence of parental care in amniotes

Here we report on a fossil synapsid, Dendromaia unamakiensis gen. et sp. nov., from the Carboniferou

New embolomerous tetrapod material and a faunal overview of the mississippian-aged point edward locality, Nova Scotia, Canada

Embolomerous tetrapods, moderately-sized to large aquatic predators, form a major faunal constituent of Permo-Carboniferous tetrapod communities. Embolomeres are recognized by their distinct circular, bipartite vertebrae. Although traditionally classified as stem amniotes, the inclusion of embolomeres within the tetrapod crown group has recently been challenged. Despite the group’s phylogenetic uncertainty, embolomeres provide an important record of a long-lived tetrapod lineage, spanning “Romer’s Gap” through to the early Permian. Here, we describe embolomerous tetrapod material that was collected in 1915 by W.A. Bell (CMN 10015, herein divided into CMN 10015A, 10015B, and 10015C). The material, composed of numerous disarticulated cranial and postcranial elements, was discovered near Sydney, Nova Scotia, Canada, as ex situ beach-float pertaining to a horizon within the Mississippian-aged Point Edward Formation. Among this material, a single left lower jaw of a proterogyrinid is identified, differing from previous embolomere remains from this site identified as Pholiderpeton(?) bretonensis Romer, 1958. We also identify an anterior jaw fragment as a separate taxon from the proterogyrinid, indicating the presence of at least two embolomerous tetrapods in Bell’s collection. Other cranial and postcranial material cannot be directly associated with either jaw and are not diagnostic enough to assign to a specific taxon. Thus, the remaining material is referred to Embolomeri indet. until more information is available. Additionally, we summarize the fauna of the Point Edward locality revealing a diverse aquatic Late Mississippian ecosystem. Finally, the extensive embolomere material described here presents new data that can broadly address embolomere diversity throughout the Carboniferous

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

The Carboniferous (Pennsylvanian; 309-307 Mya) 'Mazon Creek' Lagerstätte produces some of the earliest tetrapod fossils of major Palaeozoic lineages. Previously, the Mazon Creek record of lysorophians was known from a single poorly preserved specimen consisting only of a partial vertebral column. Here we describe a new, virtually complete lysorophian genus and species, Infernovenator steenae gen. & sp. nov. on the basis of a unique combination of characters, including a near complete circumorbital series and the retention of a postfrontal. Parsimony-based phylogenetic analysis placed the new taxon in the family Molgophidae, as sister to Brachydectes newberryi. Those results and the more generalized cranial morphology present in Infernovenator further support a recumbirostran origin of Molgophidae. Co-occurrence of two morphologically and functionally distinct molgophids in the Early Moscovian suggests a rapid and underappreciated diversification of this family in the Early Pennsylvanian

Erratum: Infernovenator steenae, a new serpentine recumbirostran from the 'Mazon Creek' Lagertätte further clarifies lysorophian origins (Zoological Journal of the Linnean Society DOI: 10.1093/zoolinnean/zlz026)

The originally published version of this article contained a spelling error in the title: Lagerst tte was misspelt as Lagert tte. This has now been corrected

Erratum: Carbonodraco lundi gen et sp. Nov., the oldest parareptile, from Linton, Ohio, and new insights into the early radiation of reptiles (Royal Society Open Science (2019) 6 (191191) DOI: 10.1098/rsos.191191)

Our originally published manuscript ‘Carbonodraco lundi gen et sp. nov., the oldest parareptile, from Linton, Ohio, and new insights into the early radiation of reptiles’ did not include the required ZooBank accession number. This is supplied here: LSIDurn:lsid:zoobank.org:pub:02676B44-D849-4ACC-8869-76D54 60E4239