Help with crocodile ID

[AnimalToyForum]

I've been going back and forth trying to ID an unidentified taxidermy crocodile specimen from West Africa in the Nottingham Natural History Museum. It's a bit emaciated. I'm writing a museum label for it and I want to get it right! I don't want to reveal what I think it is (I don't want to influence you) but I'm very interested what other people think. Any help or opinions would be appreciated. I can share more pics if needed but I've focussed on the skull and neck.


(That's our go-to taxidermist in the background working on a horseshoe crab)

(damaged scutes being repaired)


(It's got one tooth cleaned in this photo!)

[Saarlooswolfhound]

Definitely not my wheelhouse of expertise, but to me it looks like a West African slender snouted croc. It has those high set large eyes, and a very narrow snout. Emaciated or not, that skull is very gracile looking to me.

[stargatedalek]

Seconding that ID, even a young Nile doesn't have a skull anywhere near that slender.

[BlueKrono]

I may be a herpetologist, but my specialty is chelonians, not crocodilians. Still a fun exercise. I know you said this specimen was acquired in Africa, but more than any of the African species this one looks most like an American crocodile to me. How it paddled across the Pond is beyond me, but that's what I'm going with. Am I crazy?
https://commons.m.wikimedia.org/wiki/File:American_Crocodile_(49661085411).jpg

[AnimalToyForum]

Thanks all for your opinions.

Here's a illustration comparing the two slender snouted crocodile species, West African on the left. Note the arrangement of scutes (particularly the postoccipital scutes immediately behind the head), and compare them with the other species below (Americal, Nile, and Saltwater):



Does this change any of your minds?

I'm presuming its from West Africa because that's what the database says, but it isn't out of the question that's a mistake or an assumption by previous curators. So, if the anatomy is a dead ringer for a non-African species, it's worth considering.

[Saarlooswolfhound]

Looking at the scutes I am a bit confused now. If we can still trust that the specimen is from West Africa the head looks like a slender snout, but the red and purple group scutes to my eyes could pass as an American croc, but the green formations look like a Nile croc or a saltie.

But again, this is a juvenile specimen and a rather hungry looking one at that. Do the scutes change that much as crocs grow? I guess I will be doing some reading!

Terrible and quick phone edit on the photo... but the scutes in row 2 from the top are oddly arranged.

[Cenozoic Fauna]

Great photos thanks for sharing! So this is likely a very young Nile crocodile Crocodylus niloticus or a west African crocodile crocodylus suchus.

Young Nile croc with slender snout photo

Larger Nile croc with slender snout


West African croc

Young west African croc

Based on the neck scutes, it Looks to be from the Madagascar Nile crocodile population Crocodylus niloticus madagascariensis which has the same number of nuchal scutes seen on this particular specimen


That crocodile specimen might have been from Madagascar or possibly east Africa, it is indeed a Nile crocodile, based on it's scute arrangement, coloration, and morphology. Nile crocodiles are only known from certain  parts of west Africa and Angola and also parts of Gabon from what I've read, only the west African crocodile species crocodylus suchus is widely known to inhabit all the regions in west Africa. In the book Biology and Evolution of Crocodylians, it shows the geographic ranges of the Nile and west African crocodiles.

Also young Nile crocodiles have slender snout but the skulls get broader as the croc grows, and there is also distinct variations in Nile crocodile populations some have more slender snouts others, Intermediately broad to very broad,A lot of variation in skull morphology in the Nile's. The Mara river populations have very broad snouts.
Crocodiles can sometimes have more nuchal scutes on rare occasions. Seems to be the case with this specimen. It's very likely a Nile crocodile that was originally from Madagascar based on the number of nuchal scutes on the neck, or even perhaps East Africa I reckon.

Though could it be a young west African crocodile? Perhaps, but the morphology, colorations, and scute arrangement which is also seen in the Madagascar Nile croc population, id say it's indeed a nile crocodile, and likely not from west Africa, but Madagascar though what locality is uncertain, also East African is another possible location for the specimen. though there is the possibility of it being from a Gabon or Angolan nile crocodile populations which are the only known locations of nile crocs in west African that I'm aware of. But everything points to it being from Madagascar based on its nuchal scutes. Very fascinating find.

 I have seen other specimen of rare species of crocodiles such as the Congo dwarf crocodiles which are misidentified as dwarf caimans sometimes due to the skull morphology and brighter colorization in osteoalemus Osborni the Congo dwarf croc than seen in the two other dwarf crocodiles seen in west African which are darker. Also interesting there are reports of undocumented unknown croc species in remote parts of Africa such as the Congo, or central Africa, and the Cameroon. Regarding Madagascar there used to be a horned crocodile called voay robustus that was present there until the late 1900s. It was a predominantly terrestrial species that lived in swamps and large streams in the rainforest, and is related to dwarf crocodiles and slender snouted crocodiles.

[BlueKrono]

Voay in the late 1900's? Did it survive past 0 CE?

[Cenozoic Fauna]

Voay in the late 1900's? Did it survive past 0 CE?

Surprisingly yes, it would appear, originally read reports of voay robustus surviving very recent from Evon hekkala, and mentions that voay robustus was probably still around when pirates got stranded on Madagascar, and locals distinguishing two distinct crocodiles in Madagascar. Source: "Sci News Ancient DNA Sheds Light on Evolutionary History of Extinct 'Horned' Crocodile"

About the 1900s late survival of voay  there is a newer paper that mentions late 19th century of putative remnants of Voay robustus. Paper is called "Neuroanatomy and pneumaticity of the extinct Malagasy "horned" crocodile Voay robustus and its implications for crocodylid phylogeny and palaeoecology" Also it sights another paper when mentioning this detail about voay robustus which is Vaillant & Grandidier, haven't read that paper yet, could have some more intriguing details on voay.


There are is another source which has more info on late surviving voay robustus in a book called "The new natural history of Madagascar on page 1459" it also sights  Vaillant & Grandidier, I'll try to get the links.
Very fascinating. I originally thought voay prersisted up until 2000 years ago, but was quite the news to learn how recently voay robustus actually persisted.

"Edit" here are the links to the studies

Mentions of late survival of voay
https://www.sci.news/paleontology/voay-robustus-evolutionary-history-09598.html


The 1900s putative reports of voay mentioned in this study as well has its ecology
https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25367

Book mentions more about local reports of  voay robustus
https://books.google.com/books?id=IJhwEAAAQBAJ&pg=PA1459&dq=voay+robustus%C2%A0&hl=en&newbks=1&newbks_redir=0&source=gb_mobile_search&sa=X&ved=2ahUKEwi30YbrzteGAxXgLUQIHZa2CykQ6AF6BAgFEAM#v=onepage&q=voay%20robustus%C2%A0&f=false

[Cenozoic Fauna]

Also regarding the crocodile specimen
From Nottingham Natural History Museum.
Here are some slender snouted Nile crocs from Kenya and other Nile crocs from other parts of Africa 

[BlueKrono]

Fascinating! I'm going to have to dig into those sources. Thanks.

[AnimalToyForum]

Thanks everyone for your helpful comments, interestingly, the conversation here has somewhat mirrored my own journey with the specimen:

My immediate impression, based on the gracile snout and geographical information, was that it must be a West African slender-snouted crocodile. We got quite excited about this because there are fewer than 500 left in the wild. I even wrote the label with this ID. But then I dug a little deeper and started to have second thoughts. Slender snouted crocodiles have slightly upturned snouts, but this specimen doesn't, and as we discussed upthread, the arrangement of scutes doesn't match. After a bit of agonising, and looking at lots of photographs and illustrations, I came to the tentative conclusion it was an unusually long-snouted example of a juvenile Nile crocodile. The trouble with using photographs online is that you have to assume they are correctly identified.

Then I came here to see what you all thought, and you ran the full gamut of species (and more)!

@Cenozoic Fauna has made a compelling argument for the Nile crocodile. My colleague thinks it's a West African crocodile, which is very similar to Nile crocodile, so that's possible. I think we'll go for West African crocodile on the label - if that isn't exactly right, we can be forgiven.

@Saarlooswolfhound, that's an interesting observation of asymmetry in the scutes, well spotted. This sort of variation does seem quite common in crocodiles.

[Shane]

The only croc species I have any direct experience with is C. acutus and I feel pretty confident this isn't that.

C. acutus has a prominent "hump" on the snout near the eyes, which is visible in the skeletal posted above, and this taxidermy example definitely lacks that.

[Cenozoic Fauna]

@AnimalToyForum Awesome! It was cool seeing this specimen with its unusual neck scute arrangement and the amount of scutes on the neck which is not commonly seen in crocodylus species, frankly it's the first I've seen a species of crocodylus with this kinda of neck scute arrangement and the amount of scutes as well, quite unexpected, also had to do some research to. Very fascinating.

 Also There is quite a large diverse amount of crocodile species in Africa, 7 currently known species recognized! and likely more to be discovered. Regarding the crocodile specimen held at the Nottingham Natural History Museum. The West African crocodile is a likely candidate for this croc specimen, very cool to hear! Currently I do think it's a young Nile crocodile based on the size of its scutes on its back and the large nuchal scutes on its neck, and most  tantalizingly 

This particular crocodile specimen has the same number of neck scutes and also in the same arrangement has as in this nile crocodile from Madagascar.





Also nice, it could also very well be a west African crocodile with a varying degree more scutes than the norm given the variation crocodiles have in scute and osteoderm  arrangement just like in the Madagascar Nile crocodile in the photo with the same amount of neck scutes, also it can certainly be more difficult to find distinctions with the two very similar crocodylus species in Africa at a smaller size range.

Though intriguingly West African crocodiles are known to have a more flatter snout with two knob like bumps at the base, middle part of the skull, and reduced squamosal horns while Nile crocodiles have more pronounced squamosal horns which are more prominent when at larger sizes and lack the knob like bumps. It is also possible it could very well be a Madagascar Nile Crocodile based on its neck scutes and squamosal horns which is a feature I forgot to mention about Nile crocodiles previously on my original posts, as well as the distinct morphological features of the west African crocodile and the two knob like bumps, and flatter skull of the species. Though I haven't looked enough at smaller west African crocodile squamosal horns, or even smaller Nile crocodiles and compared the two to see the distinctions.

To be 100% sure on what crocodile species or locality of origin it originally is from, would need a genetic analysis done on the specimen.


Also this was really cool! I do wonder if there are other crocodile specimens at the museum as well?

[AnimalToyForum]

Thanks for the additional thoughts.

@AnimalToyForum
Also this was really cool! I do wonder if there are other crocodile specimens at the museum as well?

I can share more mystery specimens, we have lots! Maybe I will turn this thread into a general specimen ID thread.

Here's a tortoise with no provenance data that's going on display and needs identifying. I can take more photos if needed.



One for @BlueKrono maybe!? Thanks!

[stargatedalek]

A photo from above and one of the plastron would probably go a long way, if that's reasonably safe to get.

My guess from this photo is Russian tortoise, the relatively smooth shell and colouration aren't enough to give a solid ID but it's the one that comes to mind.

[Gwangi]

It's one of the Mediterranean tortoises of the Testudo genus for sure, but I'm not certain which. Stargate is right, pictures from above and below would help.

Maybe this will help!

[EpicRaptorMan]

The scute shapes and colors looks like some variants of Greek tortoise

[Gwangi]

The scute shapes and colors looks like some variants of Greek tortoise

That's what I'm leaning towards too.