jorgoristevski.bsky.social
PhD in paleontology, specializing in crocodylomorph anatomy, taxonomy and evolution. Postdoc at Max Planck Institute of Geoanthropology. He/Him/His
https://jorgoristevski.com/
23 posts
269 followers
195 following
Regular Contributor
Active Commenter
comment in response to
post
Thank you!
comment in response to
post
Can you please add me as well? Thanks in advance.
comment in response to
post
Currently, there is only one specimen that can be referred to Quinkana fortirostrum with 100% certainty - the holotype. It's not even a complete skull, it's just the upper snout.
comment in response to
post
When more material is discovered, it may be demonstrated that at least some (if not all!) of the postcranial croc elements from the Otibanda Formation could be assigned to Mekosuchinae.
comment in response to
post
The postcranial elements were more challenging to determine as to which taxon/taxa they may belong, so we provisionally referred to them as Crocodylia incertae sedis. However, some of the postcranial elements are mekosuchine-like in appearance.
comment in response to
post
The conidont (meaning conical) teeth from the Otibanda Formation probably belong to a species of the genus #Crocodylus (which has surviving species today, both in New Guinea and mainland Australia). So, we provisionally referred the conidont teeth as cf. Crocodylus sp. indet.
comment in response to
post
#Sebecosuchia is a group of extinct crocodyliforms that do not have a known fossil record from Australasia. The last known sebecosuchians went extinct in South America by the end of the Miocene. Therefore, we provisionally referred the Otibanda ziphodont teeth as ?Mekosuchinae gen. et sp. indet.
comment in response to
post
Because the ziphodont teeth from Otibanda are similar to those of ziphodont mekosuchines and they are from a time (Pliocene) and location (New Guinea, which shares A LOT of faunal similarities with Australia), it is most likely that the Otibanda ziphodont was a mekosuchine and not a sebecosuchian.
comment in response to
post
At present, there is only one named ziphodont mekosuchine genus - #Quinkana (although Quinkana was not the only ziphodont mekosuchine genus; a different conversation for a different time).
comment in response to
post
Ziphodont crocodylians inhabited mainland Australia for millions of years, and survived well into the Pleistocene. All ziphodont crocs from Australia belong to the now extinct group called #Mekosuchinae.
comment in response to
post
We also attempted to provide a more thorough and updated definition as to what ziphodont dentition is in #Crocodylomorpha (the group that includes all crocodylians and their extinct relatives).
comment in response to
post
The ziphodont teeth were the main focus of our study. #Ziphodonty is a type of dentition that is characterized by labiolingually compressed tooth crowns (i.e., longer than wide tooth crowns) that have serrated carinae (i.e., serrated front and back cutting edges).
comment in response to
post
Fast forward 57 years, I teamed up with my friends & co-authors Ralph Molnar and Adam Yates to finally examine this material in detail. What we found was 8 postcranial elements, 72 non-serrate conidont teeth and 11 #ziphodont teeth. We gave detailed descriptions accompanied by photographs.
comment in response to
post
Intriguingly, Plane (1967) also mentioned of serrated teeth that he stated “can probably be referred to the suborder Sebecosuchia”. Aside from the short paragraph dedicated to the crocodylian fossils, Plane (1967) did not provide detailed descriptions and none of this material was figured either.
comment in response to
post
The crocodylian fossils mainly consist of isolated teeth and several postcranial fragments. Plane (1967) suggested that most of the isolated teeth and the postcranial elements “can probably be referred to the genus Crocodilus” (notice the archaic spelling Crocodilus instead of Crocodylus).
comment in response to
post
The Otibanda Formation in Papua New Guinea is a fossil bearing site that has been dated as Pliocene in age. Back in 1967, Michael D. Plane published the first detailed faunal assessment of the Otibanda Formation where he briefly mentioned of fragmentary crocodylian fossils.
comment in response to
post
I completely agree that there are few artistic representations of Quinkana that make sense. We definitely need more art of Quinkana that is scientifically plausible. I'm looking forward to your upcoming depiction. Your illustration of Q. fortirostrum in the original post above looks great!
comment in response to
post
All Quinkana species are known from fragmentary craniomandibular remains. So, any artistic representation will be highly speculative by default. At least Q. fortirostrum is known from a well-preserved snout (compared to what is currently published of Q. timara) and is also the type species.
comment in response to
post
Palaeontologist that uses CT and micro-CT here. Would love to join if there is room 😊
comment in response to
post
Thanks!
comment in response to
post
Would love to join if there is a free slot available 😊