#gavialoidea

[arminreindl]

Fun little thing I just stumbled across. Apparently a male gharial is also known as a ghadiala, a term derived from the protuberance on their snout (known as a ghara after a type of earthen pot)

For those unfamiliar, here's some photos of what the ghara looks like. Photographs by Shivang Mehta

[sinasinasinas]

Thoracosaurus neocesariensis that catched a newborn mosasaur. Maastrichtian Crimea.

[arminreindl]

Today held an amazing surprise for me. For the second time ever, one of my illustrations (a silhouette) was featured in a published scientific paper. Specifically, my phylopic silhouette of Toyotamaphimeia machikanensis was used in "Crocodylian princess in Taiwan: Revising the taxonomic status of Tomistoma taiwanicus from the Pleistocene of Taiwan and its paleobiogeographic implications" courtesy of Yi-Yang Cho and Cheng-Hsiu Tsai.

A little backstory before I briefly summ up the paper. Toyotamaphimeia machikanensis (Toyotama-hime from Mountain Machikane, after a Japanese deity that took the form of a crocodile) is a tomistomine gavialoid from the Pleistocene of Japan. A fascinating animal, being found incredibly far north for a crocodilian, 6-7 meters long and with several signs of injury from combat (including a broken off lower jaw). Anyways, the paper itself does not deal with T. machikanensis directly. Instead, the authors take a look at various remains of tomistomines found on Taiwan, specifically Tomistoma taiwanicus and Toyotamaphimeia sp., concluding that both represent the same species they name Toyotamaphimeia taiwanicus. While this isn't a new discovery, it's still important research, as it contributes to how we understand tomistomines and specifically removes another animal that's clearly not Tomistoma from the Tomistoma genus. (For those unaware, much like Crocodylus, Tomistoma ended up being a dumping ground for any vaguely long-snouted crocodile).

Two things are especially interesting in addition to this revision. 1) The phylogenetic analysis. The phylogenetic analysis suggests that there was a whole group of east-asian "tomistomines" that existed from the Miocene until the Holocene. This included Penghusuchus, the oldest form from Miocene Taiwan. The tree further suggests that Penghusuchus would have eventually given rise to at least two genera. Toyotamaphimeia from Taiwan and Japan, and Hanyusuchus which lived along China's Pearl and Han Rivers (and only went extinct just 500 years ago).

The phylogeny isn't perfect, being known mostly from fragmentary fossils does mean that the group is poorly resolved, giving us a polyphyletic Toyotamaphimeia. Further one could take issue with one of the papers analysis recovering tomistomines as crocodylids, when most recent works suggest they were early gavialoids (something that is found by the authors when going purely off skull material). Regardless, such kinks notwithstanding the results do make a lot of sense and support the same broad conclusion reached by Iijima et al. 2022.

the second interesting thing is more of an untested hypothesis, but nonetheless worth pondering 2) Evolution and geography So I mean, with Penghusuchus and T. taiwanicus both being found on Taiwan, the authors reach the quite logical conclusion that this lineage could have originated on that island, only later branching out to mainland Asia and Japan. So far so good. They further point out that, aside from a juvenile in the 2-3 meter range, material of T. taiwanicus appears to be similar in size to T. machikanensis. Which, like said before, is easily in the size range of today's biggest crocodiles and even exceeds it. This is interesting given that the Japanese species lived in relatively more colder climate. So the paper suggests that Toyotamaphimeia managed to reach gigantothermy (meaning that its great size alone already aided in stabilizing the body temperature), which then helped the animal survive more easily in colder conditions after having left Taiwan in favor of Japan. I think more study is definitely needed to confirm this, ideally with better material, but its still an interesting suggestion and potential answer to explain how Toyotamaphimeia ranged as far north as it did.

I definitely recommend checking out the paper. It's a pretty interesting and fairly quick read. Crocodylian princess in Taiwan: Revising the taxonomic status of Tomistoma taiwanicus from the Pleistocene of Taiwan and its paleobiogeographic implications | Journal of Paleontology | Cambridge Core

[whalesusedtobewolves]

LOL I are gharial. I cannot eat you because my snout is too narrow to hold your weight and I am scared of you because your people are mean to me.