Henry Thomas 🦤🏳️🌈
@zhejiang0pterus.bsky.social
Paleontologist of sorts. MSc from Idaho State University. I study dicynodonts and pterosaurs, among other things. They/them
If you’re at #2025SVP, I’ll be available to chat about this work this afternoon! Our poster on it is at the very end of the balcony (left of the stage) in Hall 3.
November 13, 2025 at 12:03 PM
If you’re at #2025SVP, I’ll be available to chat about this work this afternoon! Our poster on it is at the very end of the balcony (left of the stage) in Hall 3.
The Lapworth Museum is overlooked by the most ominous clock tower on this island
November 12, 2025 at 11:35 PM
The Lapworth Museum is overlooked by the most ominous clock tower on this island
Checked in and all set for #2025SVP!!!! If you see someone with a beanie, a bunch of pride pins on their name tag and nails like obsidian - that’s me, let’s chat!
November 11, 2025 at 4:44 PM
Checked in and all set for #2025SVP!!!! If you see someone with a beanie, a bunch of pride pins on their name tag and nails like obsidian - that’s me, let’s chat!
Our recent azhdarchoid phylogeny paper has gotten a David Peters blogpost. I am now officially a pterosaurologist
November 11, 2025 at 11:00 AM
Our recent azhdarchoid phylogeny paper has gotten a David Peters blogpost. I am now officially a pterosaurologist
Lesbian flag in the Sedgwick Museum
November 8, 2025 at 12:31 PM
Lesbian flag in the Sedgwick Museum
Monodon not living up to its name
November 8, 2025 at 11:02 AM
Monodon not living up to its name
Ornithocheirus simus is distinguished by a blunted triangular surface on the front of the snout, which makes it very amenable to booping
November 7, 2025 at 12:09 PM
Ornithocheirus simus is distinguished by a blunted triangular surface on the front of the snout, which makes it very amenable to booping
Azhdarchids ancestrally had a wingspan of about 4 meters. Really big size (8-10 meters) evolved four separate times: in Cryodrakon, in Hatzegopteryx, in Arambourgiania, and in the Quetzalcoatlus northropi-Thanatosdrakon clade. Interestingly, all of these giants are geographically separated...
November 5, 2025 at 6:31 PM
Azhdarchids ancestrally had a wingspan of about 4 meters. Really big size (8-10 meters) evolved four separate times: in Cryodrakon, in Hatzegopteryx, in Arambourgiania, and in the Quetzalcoatlus northropi-Thanatosdrakon clade. Interestingly, all of these giants are geographically separated...
We reconstructed wingspan as generally increasing over time in pterosaurs, though some clades (Anurognathidae, Tapejaridae, Chaoyangopteridae, even some azhdarchids) show significant size decreases. The biggest non-azhdarchid pterosaurs include Tropeognathus (>8 meters) and Pteranodon (>7 meters)
November 5, 2025 at 6:31 PM
We reconstructed wingspan as generally increasing over time in pterosaurs, though some clades (Anurognathidae, Tapejaridae, Chaoyangopteridae, even some azhdarchids) show significant size decreases. The biggest non-azhdarchid pterosaurs include Tropeognathus (>8 meters) and Pteranodon (>7 meters)
That got us thinking - how did size evolve? How did Quetzalcoatlus et al. get big? So we performed ancestral state reconstruction using our huge pterosaur tree to trace size evolution in pterosaurs. In this diagram, the yellow-orange-red-purple gradient represents increase in wingspan
November 5, 2025 at 6:31 PM
That got us thinking - how did size evolve? How did Quetzalcoatlus et al. get big? So we performed ancestral state reconstruction using our huge pterosaur tree to trace size evolution in pterosaurs. In this diagram, the yellow-orange-red-purple gradient represents increase in wingspan
But - we find the two species of Quetzalcoatlus as not closely related! That is, the huge type species Q. northropi and the smaller Q. lawsoni are not each other's closest relatives - Thanatosdrakon and several unnamed specimens get in the way. What does this mean???
November 5, 2025 at 6:31 PM
But - we find the two species of Quetzalcoatlus as not closely related! That is, the huge type species Q. northropi and the smaller Q. lawsoni are not each other's closest relatives - Thanatosdrakon and several unnamed specimens get in the way. What does this mean???
The longest-necked azhdarchids, like Quetzalcoatlus, Infernodrakon, and Arambourgiania, form a derived clade. We name this clade Serpennata - "feathered serpents", in reference to their long necks and the earliest named genus, Quetzalcoatlus, named for Aztec feathered serpent deity Quetzalcoatl
November 5, 2025 at 6:31 PM
The longest-necked azhdarchids, like Quetzalcoatlus, Infernodrakon, and Arambourgiania, form a derived clade. We name this clade Serpennata - "feathered serpents", in reference to their long necks and the earliest named genus, Quetzalcoatlus, named for Aztec feathered serpent deity Quetzalcoatl
These three robust azhdarchids are found in eastern Europe, which was a series of islands that lacked large theropods. It's been proposed before that Hatzegopteryx filled land predator niches in their absence, but it's possible the entire clade was going down this route!
November 5, 2025 at 6:31 PM
These three robust azhdarchids are found in eastern Europe, which was a series of islands that lacked large theropods. It's been proposed before that Hatzegopteryx filled land predator niches in their absence, but it's possible the entire clade was going down this route!
We also find the Hungarian Bakonydraco within this clade. Many recent phylogenetic studies find it as a tapejarid, but it shares a LOT of similarities with Albadraco and Hatzegopteryx under closer inspection. We corrected its codings and find it as an azhdarchid, as originally described!
November 5, 2025 at 6:31 PM
We also find the Hungarian Bakonydraco within this clade. Many recent phylogenetic studies find it as a tapejarid, but it shares a LOT of similarities with Albadraco and Hatzegopteryx under closer inspection. We corrected its codings and find it as an azhdarchid, as originally described!
We also recover a clade containing the robust, short-necked eastern European azhdarchids Albadraco and Hatzegopteryx. Hatzegopteryx is known from a bunch of isolated material - we coded it separately to test this, but they're still united by a unique bone texture - very thick and spongy
November 5, 2025 at 6:31 PM
We also recover a clade containing the robust, short-necked eastern European azhdarchids Albadraco and Hatzegopteryx. Hatzegopteryx is known from a bunch of isolated material - we coded it separately to test this, but they're still united by a unique bone texture - very thick and spongy
In azhdarchids proper, we recover a similar general topology to other recent studies. The first branch, Phosphatodraconia, contains a few species with very cylindrical neck vertebrae and possibly short beaks (see below). Then a Zhejiangopterus-Aerotitan-Mistralazhdarcho clade, then Azhdarcho itself
November 5, 2025 at 6:31 PM
In azhdarchids proper, we recover a similar general topology to other recent studies. The first branch, Phosphatodraconia, contains a few species with very cylindrical neck vertebrae and possibly short beaks (see below). Then a Zhejiangopterus-Aerotitan-Mistralazhdarcho clade, then Azhdarcho itself
The North American azhdarchoids Radiodactylus and Montanazhdarcho have separately been recovered as being the closest relatives to azhdarchids proper. We find them as forming a clade. They join azhdarchids, alanqids, and chaoyangopterids within another newly named clade, Concilazhia
![Skeletal reconstruction of Montanazhdarcho minor by Scott Hartman. It portrays it as a short-beaked azhdarchoid with a moderately long neck. Scale bar represents 25 cm. The text reads:
Montanazhdarcho minor (Padian, et al., 1995)
Known from a pectoral girdle and most of a forelimb and little else, Montanazhdarcho is none-the-less more complete azdarchids [sic] known. Neck length is restored as an intermediate between Zhejiangopterus and shorter, isolated Romanian cervicals. The skull is restored after "snub-nosed" Javelina mandible TMM 42489-2.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:kakybnmtw6vcdpkmlzlkir6h/bafkreibmyai2njc2u7x32znu5h4onxhh2yff2qn5jfoscmw555f5t5imw4@jpeg)
November 5, 2025 at 6:31 PM
The North American azhdarchoids Radiodactylus and Montanazhdarcho have separately been recovered as being the closest relatives to azhdarchids proper. We find them as forming a clade. They join azhdarchids, alanqids, and chaoyangopterids within another newly named clade, Concilazhia
Within Chaoyangopteridae, we find the recently described Meilifeilong as closely related to Shenzhoupterus. We name a new clade for them, Shenzhoupterinae, characterized by relatively short beaks and very deep skulls
November 5, 2025 at 6:31 PM
Within Chaoyangopteridae, we find the recently described Meilifeilong as closely related to Shenzhoupterus. We name a new clade for them, Shenzhoupterinae, characterized by relatively short beaks and very deep skulls
Surprisingly, the recently described azhdarchoid Inabtanin (pictured) and the poorly understood Microtuban are recovered as basal azhdarchomorphs. This suggests that there was a really long ghost lineage of short-necked basal azhdarchomorphs lasting to the end of the Cretaceous in west Asia. Neat!
November 5, 2025 at 6:31 PM
Surprisingly, the recently described azhdarchoid Inabtanin (pictured) and the poorly understood Microtuban are recovered as basal azhdarchomorphs. This suggests that there was a really long ghost lineage of short-necked basal azhdarchomorphs lasting to the end of the Cretaceous in west Asia. Neat!
Some highlights:
- There are a few alleged azhdarchids from the Late Jurassic/Early Cretaceous. We find all of them as ctenochasmatoids, which also had long necks
- Three hard-to-place azhdarchoids - Bennettazhia, Vectidraco, and "Palaeornis" cliftii - we find as related to Tapejara and Sinopterus
- There are a few alleged azhdarchids from the Late Jurassic/Early Cretaceous. We find all of them as ctenochasmatoids, which also had long necks
- Three hard-to-place azhdarchoids - Bennettazhia, Vectidraco, and "Palaeornis" cliftii - we find as related to Tapejara and Sinopterus
November 5, 2025 at 6:31 PM
Some highlights:
- There are a few alleged azhdarchids from the Late Jurassic/Early Cretaceous. We find all of them as ctenochasmatoids, which also had long necks
- Three hard-to-place azhdarchoids - Bennettazhia, Vectidraco, and "Palaeornis" cliftii - we find as related to Tapejara and Sinopterus
- There are a few alleged azhdarchids from the Late Jurassic/Early Cretaceous. We find all of them as ctenochasmatoids, which also had long necks
- Three hard-to-place azhdarchoids - Bennettazhia, Vectidraco, and "Palaeornis" cliftii - we find as related to Tapejara and Sinopterus
They belong to a larger clade, Azhdarchoidea, which also contains tapejarids, thalassodromids, chaoyangopterids, and alanqids. Relationships between pterosaurs in this clade can still be versial, and many azhdarchoids have never had their evolutionary relationships phylogenetically tested
November 5, 2025 at 6:31 PM
They belong to a larger clade, Azhdarchoidea, which also contains tapejarids, thalassodromids, chaoyangopterids, and alanqids. Relationships between pterosaurs in this clade can still be versial, and many azhdarchoids have never had their evolutionary relationships phylogenetically tested
Azhdarchids are a pretty cool pterosaur clade. They're noteworthy for containing the largest flying animals that ever existed, with maximum wingspans around 10 meters. But not all of them were that big. The average azhdarchid (e.g. Infernodrakon) was around 4-5 m in wingspan - about person height
November 5, 2025 at 6:31 PM
Azhdarchids are a pretty cool pterosaur clade. They're noteworthy for containing the largest flying animals that ever existed, with maximum wingspans around 10 meters. But not all of them were that big. The average azhdarchid (e.g. Infernodrakon) was around 4-5 m in wingspan - about person height
