Search the Community
Showing results for tags 'crocodilians'.
-
- 4 replies
-
- crocodilians
- dorsal vertebrae
-
(and 1 more)
Tagged with:
-
One for the (marine) crocodile specialist...
pachy-pleuro-whatnot-odon posted a topic in Questions & Answers
Hi everyone, Recently, while researching the morphology of machimosaurid crocodile teeth, I bumped into the below specimen, identified as Machimosaurus hugii (presumably based on its size). And although I can't confirm the specific name, I'm confident the referral to Machimosaurus is correct. When taking a closer look at the tooth's striations, however, I noticed not all of them actually run the whole apicobasal length of the tooth as I expected. And although some striations have undoubtedly been terminated and/or interrupted by wear, I was more genetically wondering if striations not running the full apicobasal length of the tooth is a know characteristic of crocodile teeth. For I'm only familiar with teeth that are either entirely smooth, or that have fine striations on one or both sides of the tooth, where only those striations that run into one of the tooth's carinae may be truncated before reaching the full apicobasal length of the tooth. That having been said, though, I can imagine crocodilian dental ornamentation being more varied, with different patterns of organisation in their striations, as Madzia (2016, A reappraisal of Polyptychodon (Plesiosauria) from the Cretaceous of England), in an annotation with his figure 8 illustrating pliosaurid tooth crown morphologies following Tarlo (1960) (reproduced below), observes that the teeth with the most striae, previously referred to Simolestes nowackianus, are now considered Machimosaurus nowackianus. And with the great variation of expression in striations on pliosaurian teeth, I don't think it would be such a leap to assume the same for this species of teleosaur... So, my question is: are striations on crocodilian teeth as variable as they are amongst pliosaurs? Can individual striae end prior to stretching the full apicobasal length of the tooth, and, if so, in which clades or under what conditions? Do crocodilian teeth exhibit patterns of striations of interchanging lengths (e.g., short-long-short)? Thanks for your help!- 14 replies
-
- 2
-
- crocodiles
- crocodilians
- (and 7 more)
-
Is it generally impossible to distinguish different croc species, even from just half a dozen from a certain location, by most individual bones, like humerus’/arm/leg bones, and individual verts? I know experts can definitely do so if they have the bone in-hand, and proper tools, but in THIS situation, through just pics, there’s not much that can be done unless there’s something that stands out, like unusually large size or something, is there?
- 3 replies
-
- crocodiles
- crocodilians
-
(and 2 more)
Tagged with:
-
Hello Everyone! Seems to be a good bit of interest in this topic, so I thought I’d make a little summary on what types of crocodilians you may find along the Calvert cliffs. Most of this information is gleaned from Dr. Robert Weems’ “Crocodilians of the Calvert Cliffs” in Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA, available freely by clicking the underlined portion. I encourage you to read that for more detail. If you have anything to add or you notice any mistakes, please let me know! Thecachampsa This genus is the only described genus along the cliffs, of which two species are described in this area. Among extant (living) creatures, it is most closely related to the false gharial. All large non-shark coprolites along the cliffs are assumed to be produced by Thecachampsa. Their vertebrae, like all reptile vertebrae, have a convex side and a concave side, making their vertebrae look like they have a ball and a socket. Their osteoderms are distinctive, with thick, blunt sections between the pits. Osteoderm associated with T. sericodon, from “Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA”
-
Hey all, yesterday my wife (CCNHM collections manager Sarah Boessenecker) and I wrote about some of our recent finds from Folly Beach, SC. Collecting fossils there is quite easy, and if you're there for non-shark teeth, there's essentially no competition since that's all anyone ever looks for there. The fossils of Folly Beach have never been written up, and I'm getting more and more curious about them - particularly fossil marine mammals. If anyone finds marine mammal earbones out there, I'm dying to take a look! We've already gotten a nice donation from Ashby Gale, Edisto SP ranger, of a pygmy sperm whale periotic. Here's the blog post with some images of our recent finds - including my first giant armadillo scute (Holmesina), an Alligator osteoderm, various shark and mammal teeth, and a snake vertebra. I've made a plan to go out to Folly once a week this entire semester, since it's only a 15-20 minute drive from College of Charleston (a very nice escape from campus and teaching) http://blogs.cofc.edu/macebrownmuseum/2017/02/03/friday-fossil-feature-it-would-be-folly-to-pass-this-site-up/
- 7 replies
-
- 6
-
- bony fish
- crocodilians
- (and 9 more)