zhejiangopterus
Online home of Henry Thomas, paleontologist and overall natural history geek
Publications
- Thomas, H.N.; McDavid, S.N. (2025). "Enter the dragons: the phylogeny of Azhdarchoidea (Pterosauria: Pterodactyloidea) and the evolution of giant size in pterosaurs". Journal of Systematic Palaeontology 23(1): 2569368. DOI: 10.1080/14772019.2025.2569368.
- Ravesloot-Chavez, M.M.; Van Dis, E.; Fox, D.; Anaya-Sanchez, A.; Epsich, S.; Nguyenla, X.H.; Rawal, S.; Samani, H.; Ballinger, M.; Thomas, H.; Kotov, D.I.; Vance, R.E.; Nachman, M.W.; Stanley, S.A. (2025). "Tuberculosis susceptibility in genetically diverse mice reveals functional diversity of neutrophils". eLife 13: RP102441. DOI: 10.7554/eLife.102441.2.
My middle initial got changed somehow during the proofing process! - Thomas, H.N.; Angielczyk, K.D.; Peecook, B.R. (2025). "The first geikiid dicynodont, Aulacephalodon kapoliwacela, sp. nov. (Therapsida, Anomodontia), from the upper Madumabisa Mudstone Formation, Zambia". Journal of Vertebrate Paleontology 45(sup1): e2446603. DOI: 10.1080/02724634.2024.2446603
- McDavid, S.N.; Thomas, H.N. (2025). "The putative pterosaur tracks at Gunston Hall (Potomac Group, Cretaceous of Virginia) are examples of erosion". The Mosasaur 14: 13-21. DOI: 10.5281/zenodo.14991720.
- Thomas, H.N.; Hone, D.W.E.; Gomes, T.; Peterson, J.E. (2025). "Infernodrakon hastacollis gen. et sp. nov., a new azhdarchid pterosaur from the Hell Creek Formation of Montana, and the pterosaur diversity of Maastrichtian North America". Journal of Vertebrate Paleontology 44(4): e2442476. DOI: 10.1080/02724634.2024.2442476.
Research
I'm interested in a wide variety of paleontological and biological topics, and I'm particularly fascinated by how lineages of tetrapods evolve morphologies, behaviors, and ecologies in response to differing environmental pressures. Here are some quick summations of the research projects I have been a part of.
Pterosaur evolution and diversity
Since the beginning of my undergraduate degree, I've been looking into the evolution of pterosaurs. I'm particularly interested in the evolution of the toothless azhdarchoid pterosaurs. In February 2025, I published a redescription of the only diagnostic pterosaur material from the Hell Creek Formation. This specimen, a cervical vertebra, is distinct from every other pterosaur taxon. My coauthors and I assigned it to a new genus and species, Infernodrakon hastacollis. In November 2025, I published a reanalysis of azhdarchoid phylogeny and a reconstruction of wingspan evolution within pterosaurs. We recovered several novel relationships within Azhdarchoidea and evidence for multiple appearances of giant size within azhdarchids, indicating widespread evolutionary pressure for size increase. I am involved in the descriptions of several other new pterosaur taxa and morphotypes.
Luangwa Basin geikiids
For my Master's degree, I described a new species of geikiid dicynodon, Aulacephalodon kapoliwacela. This species is known from material collected from the upper Madumabisa Mudstone Formation in Zambia, which dates to the late Permian. This new species, the only geikiid known from Permian Zambia, bolsters faunal similarities between Permian paleocommunities in the Karoo Basin in South Africa and the Luangwa Basin in Zambia. A. kapoliwacela is present in both preliminarily identified fossil assemblages, and demonstrates a relatively complete ontogenetic sequence and evidence for substrate-based foraging. I am also looking at broader patterns in phylogenetics and evolution of dentition in Permian dicynodonts.
This research was done as part of the Peecook Lab at Idaho State University, and was funded by the University and the Paleontological Society.
Hyperoliid frog evolution
I am currently involved with research on the African frog clade Hyperoliidae. I am using ancestral state reconstruction to trace evolution of anatomy, biogeography, and habitat usage in this clade.
This research is done as part of the Bell Lab at the California Academy of Sciences.
Analysis of documentary portrayals of paleontology
My collaborators and I have been undertaking an exhaustive stastistical analysis of documentary films and televisions that feature paleontology and prehistoric life, to quantify biases in what and who are portrayed on screen. We presented our results at the 2023 Society of Vertebrate Paleontology conference, and are preparing a manuscript.
Pennsylvanian swamp forest paleoecology
During the Carboniferous period, roughly 310 million years ago, humid, swampy forests covered the global tropics. These forests harbored a great diversity of strange and unusual plants, including arborescent lycopods, sphenopsids, and cordaitales. During this time, icehouse conditions led to periodic changes in sea level, which are recorded in the rock record as cyclothems. When these plants died, their remains fell into the anoxic swamps, and over millions of years of fossilization these peat swamps were compressed and transformed into coal deposits. However, limestone nodules ("coal balls") often formed in this peat, and these preserve remains of plant tissues in exquisite detail.
The Phillips Coal Ball Collection is a massive dataset of plant occurrences recorded in these coal balls, collected by Tom L. Phillips and his grad students. I helped with the digitization of this dataset, which has allowed paleoecological analysis on an unprecedented scale. With the newly-digitized dataset, I helped run analyses of shifts in community composition of the floras in this dataset across space and time.
This research was done as part of the Looy Lab at the University of California Berkeley, and was sponsored by a Chemical Society of America PRF Grant and a UC Berkeley URAP Summer Research Award.