Bryan M Gee

Bryan M Gee
University of Washington Seattle | UW · Department of Biology

Doctor of Philosophy

About

46
Publications
6,002
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197
Citations
Introduction
I am currently a postdoctoral researcher at the University of Washington in the lab of Dr. Chris Sidor. I obtained my B.A. in Geology from Pomona College (2012-2016) and my Ph.D. in Ecology & Evolutionary Biology at the University of Toronto (2016-2020). My research focuses on the evolution of early amphibians (temnospondyls) from the Carboniferous to the Triassic using a variety of methods such as bone histology and computed tomography (CT).
Education
August 2016 - June 2020
University of Toronto
Field of study
  • Ecology & Evolutionary Biology
September 2012 - May 2016
Pomona College
Field of study
  • Geology

Publications

Publications (46)
Article
Full-text available
Metoposaurids are temnospondyl amphibians that are commonly recovered from the Chinle Formation deposits of North America. Two species, Koskinonodon perfectus and Apachesaurus gregorii , are known from Petrified Forest National Park (PEFO), AZ. Small, elongate intercentra are the single diagnostic postcranial characteristic of the smaller A. gregor...
Article
Full-text available
Teeth are often thought of as structures that line the margins of the mouth; however, tooth-like structures called odontodes are commonly found on the dermal bones of many Palaeozoic vertebrates including early jawless fishes. 'Odontode' is a generalized term for all tooth-like dentine structures that have homologous tissues and development. This d...
Article
Full-text available
Abstract Doleserpeton annectens is a small‐bodied early Permian amphibamiform, a clade of temnospondyl amphibians regarded by many workers to be on the lissamphibian stem. Most studies of this taxon have focused solely on its anatomy, but further exploration of other aspects of its paleobiology, such as developmental patterns, is critical for a bet...
Article
Trematopids are a clade of terrestrial Permo-Carboniferous temnospondyl amphibians. The intrarelationships of this clade are poorly known. This is largely attributable to a substantial disparity in size between type specimens, which range from the small-bodied lectotype of Mattauschia laticeps (< 4 cm skull length) to the large-bodied holotype of A...
Preprint
Full-text available
Phylogenetic analyses and their resultant tree topologies underlie paleobiological studies. Regardless of the type of study, the relationships of focal taxa are foundational, whether implemented in a qualitative or a quantitative framework. This reliance places a premium on the continued refinement of both phylogenetic methods and inference. Temnos...
Article
Full-text available
Temnospondyl amphibians are common in non-marine Triassic assemblages, including in the Fremouw Formation (Lower to Middle Triassic) of Antarctica. Temnospondyls were among the first tetrapods to be collected from Antarctica, but their record from the lower Fremouw Formation has long been tenuous. One taxon, ‘ Austrobrachyops jenseni ,’ is represen...
Article
Full-text available
The phylogenetic relationships of most Paleozoic tetrapod clades remain poorly resolved, which is variably attributed to a lack of study, the limitations of inference from phenotypic data, and constant revision of best practices. While refinement of phylogenetic methods continues to be important, any phylogenetic analysis is inherently constrained...
Article
Full-text available
The early Permian Richards Spur locality of Oklahoma has produced abundant material of numerous terrestrial fossil tetrapods, including various “microsaurs,” several of which are considered to belong to the clade Recumbirostra. We present a new partial skull of the recumbirostran “microsaur” Nannaroter mckinziei ; through computed tomography (CT) a...
Article
Metoposaurids are some of the most commonly occurring tetrapods in non-marine Upper Triassic sediments in the northern hemisphere of Pangea. Since the first description of a metoposaurid in 1842, nearly two dozen species have been named, but many of these have been regarded with increasing skepticism by modern workers because of minor differences u...
Article
The fossil record of temnospondyl amphibians in the immediate wake of the Permo-Triassic mass extinction captures extensive taxic and ecological diversity, with most records known from high paleolatitudinal settings. In southern Pangea, the most substantial records come from South Africa and Australia, with a total of over 20 taxa presently recogni...
Article
Metoposaurids are a widespread and ubiquitous constituent of Late Triassic non-marine paleoenvironments. In North America, this group is practically the only large-bodied temnospondyl clade, and is particularly well documented from the American southwest and south-central regions (Arizona, New Mexico, Texas). However, metoposaurids are poorly docum...
Article
The dissorophid genus Conjunctio (Temnospondyli) is poorly characterized, known only from two incomplete specimens from the upper El Cobre Canyon Formation (lower Permian), Cutler Group, New Mexico, U.S.A. Nonetheless, the taxon’s conserved morphology and stratigraphic occurrence near the Carboniferous–Permian boundary (ca. 299 million years ago) m...
Article
Full-text available
'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 novel conclusion highlights the need for additional work to evaluate these competing hypotheses with the aim of refining the phylogenetic position of 'micr...
Article
Full-text available
Seymouria is the best known of the seymouriamorphs, a group of Permo-Carboniferous reptiliomorphs with both terrestrial and aquatic taxa. The majority of research on Seymouria has focused on cranial anatomy, with few detailed descriptions or illustrations of the postcrania. We utilized neutron computed tomography (nCT) and histological sampling to...
Article
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 provided substantial new data on poorly known anatomy that informs their debated phylogenetic position. Recent studies have identified suites of features...
Article
Dissorophoids are a diverse clade of predominantly Permo‐Carboniferous temnospondyls with a wide geographic distribution and broad ecological diversity. Each of the various dissorophoid clades first appears in the late Carboniferous, but their records are relatively sparse and fragmentary compared to those of the early Permian when dissorophoids re...
Article
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 on the amniote stem between temnospondyl amphibians and crown amniotes and are thus frequently used in phylogenetic analyses of both early amniotes and, more bro...
Article
Full-text available
Varanopids are a basal clade of small- to medium-sized nontherapsid synapsids, whose range extends from the late Pennsylvanian to the late middle Permian, and are found in North America, Russia, Europe and South Africa. The greatest varanopid diversity is observed at the fossiliferous cave deposits near Richards Spur, Oklahoma, well known for the p...
Article
Nanobamus macrorhinus Schoch and Milner, 2014 is a small amphibamiform temnospondyl from the early Permian Arroyo Formation of Texas. It is most readily characterized by an elongate and partially subdivided naris. This condition is superficially reminiscent of that seen in the coeval trematopids, the group to which N. macrorhinus was originally ref...
Article
Metoposaurids are non-marine temnospondyls that are among the most common constituents of Late Triassic deposits, but despite their abundance, the evolutionary relationships of the group are poorly resolved and have not been fully addressed with modern phylogenetic methods. The genus Anaschisma is one of a number of poorly resolved metoposaurid tax...
Article
Full-text available
Trematopids are a clade of terrestrial dissorophoid temnospondyls documented primarily from terrestrial Permo-Carboniferous environments in North America and Europe. Here we describe the complete skull and articulated mandibles of a diminutive trematopid specimen (OMNH 79318) from the Early Permian karst deposits near Richards Spur, Oklahoma. Based...
Article
Full-text available
The Hapsidopareiidae is a group of “microsaurs” characterized by a substantial reduction of several elements in the cheek region that results in a prominent, enlarged temporal emargination. The clade comprises two markedly similar taxa from the early Permian of Oklahoma, Hapsidopareion lepton and Llistrofus pricei , which have been suggested to be...
Article
Full-text available
The Permian temnospondyl Fayella chickashaensis from Oklahoma, a purported member of the intriguing clade of terrestrially adapted dissorophids, has been difficult to contextualize within the clade because of uncertainties related to the holotype, an isolated and badly weathered neurocranium. However, postcranial material that has been attributed t...
Article
The Texas red beds represent one of the richest series of early Permian deposits in the world. In particular, the Clear Fork Group has produced a diverse assemblage of temnospondyls, early reptiles, and synapsids. However, most of this material has been sourced from the oldest member, the Arroyo Formation, and the understanding of the paleoecosyste...
Article
Alegeinosaurus aphthitos is a poorly known dissorophid from the early Permian Arroyo Formation of Texas that is represented by a partial articulated block of postcrania, including an articulated pectoral girdle, portions of the ribcage, and articulated vertebrae with osteoderms. It is one of several dissorophid taxa whose placement within the famil...
Article
Metoposaurids are Late Triassic temnospondyls that are abundant components of freshwater depositional settings. Although metoposaurids are represented by hundreds of specimens in collections around the world, the vast majority pertain to large-bodied, relatively mature individuals, and as a result, the early stages of ontogeny are still poorly char...
Article
The armored dissorophid Cacops morrisi is one of many anamniote taxa preserved at the speciose early Permian karst deposit near Richards Spur, Oklahoma. The taxon was previously known only from two isolated skulls representing a juvenile individual and an adult individual. Here we describe one partial and two complete new skulls of juvenile and sub...
Article
Full-text available
The early Permian karst system near Richards Spur, Oklahoma preserves a diverse assemblage of terrestrial dissorophoid temnospondyls. Here we report the presence of a large-bodied dissorophine dissorophid that is represented by an articulated anterior trunk region, including a partial pectoral girdle, a ribcage characterized by extremely developed...
Article
Metoposaurids are typically large-bodied freshwater temnospondyls that are among the most commonly recovered vertebrate fossils in Late Triassic nonmarine deposits. Traditional interpretations of metoposaurid evolution have argued in favor of a size turnover in the southwest of North America from the large-bodied Koskinonodon in the early Norian to...
Article
Full-text available
Denticles are small, tooth-like protrusions that are commonly found on the palate of early tetrapods. Despite their widespread taxonomic occurrence and similar external morphology to marginal teeth, it has not been rigorously tested whether denticles are structurally homologous to true teeth with features such as a pulp cavity, dentine, and enamel,...
Data
Histological sections of ROM 76838 imaged with a lambda filter illustrating major features of palatal plate anatomy (A) TS01135; (B) TS01137; (C) TS01140; (D) TS01144. Scale bar = 500 µm.
Article
Full-text available
Metoposaurids are temnospondyl amphibians that are well known from Upper Triassic deposits in North America, Europe, India, and Africa. Two species of metoposaurids, Koskinonodon perfectus and Apachesaurus gregorii, are among the most common fossils found in the Petrified Forest National Park (PEFO) of the southwestern United States. The two are di...

Projects

Projects (3)
Project
Determine baseline taxonomy, anatomy, and phylogenetic history of Late Triassic fossils from the Chinle Formation at Petrified Forest National Park and neighboring regions.
Project
Exploration of patterns of morphological evolution in metoposaurid temnospondyls, with a primary focus on the North American taxa. Methods include bone histology, phylogenetics, and descriptive anatomy.
Project
To attain unprecedented digital excavation and interpretation of fossilised remains through the use of neutron and synchrotron X-ray micro-CT as complementary contrast modalities in palaeontology. A primary aim of this project is to utilise neutron imaging as a means of imaging remnant soft-tissue structures (skin, muscle, hair, feathers, nervous structures) and other delicate material that are typically lost during physical extraction, or cannot be resolved using X-rays. Open for collaboration and keen to discuss your specimens!