Naked Science Forum
Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: Mizz Em on 26/02/2008 16:58:07
-
Hello and thank you for looking! My name is Em and I have an eight year old who is OBSESSED with dinosaurs and fossils. He has a very eclectic great aunt who has sent him some fossils and we need help identifying them for a school presentation. This is what I know of them:
-The large jaw-only one is appx 17"x6", the teeth range from appx 1" to 1.5". It was sent to his aunt from the Northern region of Africa (Sahara Desert).
-The smaller head and neck one is approx 6.5" (skull only), and was sent from the same region.
I have no idea how old these are or what species they are. I am just desperate to have SOME ideas!
Thanks so much and feel free to ask more questions. I just may have the answers =) [ Invalid Attachment ] [ Invalid Attachment ] [ Invalid Attachment ] [ Invalid Attachment ] [ Invalid Attachment ]
-
When my young daughter asked someone to identify her 2 fossils she was told they were her mum & dad [:(]
-
Haha!! That's funny... his dad and I were actually joking around about that last night [;D]
-
The area probably rules these out but thats what they remind me of!
The last one looks like a baby crocodile maybe the top one mamas jaws!!
Not the right places though! Different places but same region..?
-
From what I know, same region. She got them from a gentleman in Morocco, a year apart from each other. She doesn't know much about them either [:-\]
-
Well regardless of what they are, they are indeed very cool! and even with the information you have.... allowing the children and teacher to make a project out of collecting a list of possible dessert creatures which may have been indigenous of the region. It could make for a great class project.... Very cool.... by the way nice to see you back... good luck to you Em !!
-
As there are no qualified vertebrate paleontologist here I will do my best as a plain ol' geologist to answer the question but I will only be a general answer, not a specific answer.
Both are carnivorous dinosaurs, unless they are from a more recently laid down rock. In this case they would be crocodilian reptiles younger than dinos - 65 Million years or younger.
The upper tan fossil is probably a crocodilian of either Mesozoic or younger age as the teeth are similar to those of living crocodiles. You have only the maxillary and mandibular part of the jaw. Without the skill bones much more differentiation would be difficult. A vertebrate paleontologist would be able to help much more than I.
The other is also possibly a crocodilian but I cannot really tell. It could very well be a carnivorous dinosaur with which I am absolutely unfamiliar. Can you provide a side view of the grey-with-neck-bones fossil? The teeth could tell me a lot. Either of the people I am referring you to below would want as much detail of the skull as possible. Please contact them. I am at the limits of my knowledge already!
Professor Emeritus Wann Langston - wannl@mail.utexas.edu - is somewhat of an expert on crocodiles. If he doesn't answer your email, Professor Emeritus Ernnie Lundelius - erniel@mail.utexas.edu - can help you. I know Ernie goes to the lab every day; I am not sure about Doctor Langston. And Ernie is a neat guy. I worked for him long ago.
-
Maybe this site has no vertebrate paleontologist as such - but it does have an amazing rodent who just happens to know a bit about crocodiles.
I think the lower relic is Crocodylus cataphractus (African slender-snouted crocodile aka African gharial) or an ancestor thereof. The teeth on the relic are a bit wrong, so my guess would be that it's an ancestor.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F0%2F05%2FCrocodylus_cataphractus.jpg%2F800px-Crocodylus_cataphractus.jpg&hash=39d5cbd4d70d3378bed9d7d7b39db4cb)
image from Wikipedia
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.digimorph.org%2Fspecimens%2FCrocodylus_cataphractus%2Fspecimen.jpg&hash=33f8d134b4ec228cea3b5e70af3cf60e)
image from www.digimorph.org
In this image there appear to be circular marks on the top of the skull that are similar to those on the relic.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fmongabay.com%2Fimages%2Findonesia%2Fzoo%2Fz8703.JPG&hash=e8b8ef7be8a03ecd3d48c7e7d11805aa)
image from travel.mongabay.com
This creature is found in West Africa south of the Sahara desert, so Morocco is on the right continent and within fairly easy trading distance.
Here is a map of where they can be found
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.flmnh.ufl.edu%2Fcnhc%2Fimages%2F%21csm-ccat.gif&hash=ae7c7e56390b0955203a0d23630309af)
(image from flmnh.ufl.edu)
-
The skull structure is why I am interested in close up views and side views. The picture you showed of the skull (thank you, Eth) is going to have an oblong shape viewed from the top. These posterior holes are more massive in the recent specimen. These gaps in the skull are where the muscles that provide the bite force for the animal are located. I believe you are correct that it is an ancestor of the present one. And not a dinosaur. The tan one is probably older but not by much.
The Sahara, including Morocco, was a savanna with abundant water supply up until ~ 11-13,000 years ago. There was until recently a very small family of Saharan Crocs at a water hole deep within the desert but I believe it is now either down to one female or totally gone now. the crocs lived off migrating birds and small desert mammals.
-
The tan 1 is not a croc; the teeth are all wrong.
It certainly isn't a gharial, the teeth of which are long & thin. Crocs have teeth that overlap the lip on the opposing jaw which is clearly not the case in the relic. Plus their teeth are irregular. Those in the relic are even and more-or-less the same along the whole length of the jaw.
Plus, the number of teeth in the tan relic is wrong. Crocs have 68-70, Alligatorids have 80 to 88, Tamistoma about 80, and Gavialis about 110. The relic has 30 at most.
The relic's teeth are in good condition with very few chips. That would imply either that it fed on very fleshy animals (where it didn't have to chew on bone) or that its teeth were constantly renewed; unless, of course, it is a young animal that died. Although crocodiles' teeth renew, as I stated, the relic's teeth are wrong in shape and quantity.
I also note that there are no visible nasal openings. If they are at the tip of the snout, that would point to a creature that spent its time in the water with the end of its snout above the surface like a croc. However, it is possible that this creature didn't have nasal openings at all because it was a fish.
Its teeth are certainly reminiscent of those found in some types of shark and that would also confirm what I said about it not having to chew on bone. If I had to put money on it, I think I would go for it being a piscine jaw.
-
Wow... thank you all so much for the help so far! What a wonderful site I 've stumbled across!
Here are some more views of the skull with vertebrae. I'm sorry they aren't SUPER duper close up, my camera isn't the best [:P]
And again... thank you all!
-
Undoubtedly crocodilian. The 2 overlapping teeth at the front are typical of crocs. And I'm even more sure it's an African gharial (the teeth are wrong for an Indian gharial) - albeit a young one. The shape of the skull certainly points to that.
If you look at the number of overlapping teeth there are not enough for a modern-day gharial. That's why I think it was an ancestor.
I'm glad you like the site and become a regular contributor.
-
Jim - just a couple of thoughts on the tan fossil.
Is that an eye socket at the top left? It's a bit irregular, but definitely could be, I think.
Something else that interests me about it is that there is no indication of the top part joining to the bottom. Do you think that maybe the posterior end of the bones have been eroded? Either this creature had a very pronounced snout of which this fossil is only a part, or the jaws didn't join at all. Judging by the size & shape of the teeth, and the fact that they do not overlap outside the line of the bone, this creature would have had a lot of trouble closing its mouth completely. I can't think of any mammal or reptile where that is the case.
Taking all that into account makes me even more convinced it's a fish.
-
No fish - there are no living or fossil fish that have teeth like this. Not unless you go way back to the Silurian do fish have teeth such as these.
I do agree that the full skull is an ancestor of the present croc referenced above. The brown one is an old crocadillian, much older than the grey one. This one -
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi38.photobucket.com%2Falbums%2Fe111%2Fgeezer69%2FGavialosuchus.jpg&hash=8ca2a690984d1319f054107f7f159506)
Gavialosuchus
- is about two thirds of the way closer to present crocs than the tan specimen. It is from the Miocene (7-23 Milion years ago.) Note that the teeth are a little more regular, some have the scimitar shape of the tan specimen but I am not guaranteeing it is a croc. But both the tan one and the Miocene fossil have two types of teeth, some the Curved ones of a meat eater and some the cone shaped ones of crocs that hold croc pray in place while it drowns. It also could very well be the jaws of a predatory dino. It is only a partial jaw, as you suspect. The snout is to the right, this is the smooth end and the curved teeth are always pointed towards the rear.
The teeth are the most important part of this specimen. What we see is only part of the teeth, both the roots and ends are enclosed in matrix (the sand containing the skull.) They are more similar to the teeth of a T-Rex than a croc. That is why I say that if it is a croc, it is very old, before the Miocene.
-
I am truly amazed at the responses I have gotten so far [;D] This began as a shot in the dark for me and I never anticipated I would recieve so much useful information! DoctorBeaver, JimBob... my sincerest thanks! My son is so fascinated by all of this and is eager to share with his class.
And I'm still open to more info!!
[;)]
-
If it's a croc, where are the nasal openings? In the image you posted, one is clearly visible at the end of the snout. There is not even a slight indentation on the fossil.
The teeth in your image certainly have the right colouration, but there are no incisor-like teeth in the fossil except for maybe the front pair and another at #3.
Also, look at the bottom of the upper bone in your image and compare it with the fossil. The 1 in your image is like a rollercoaster; totally different from the fossil.
I have to disagree with you about there being no living fish with teeth like those in the fossil. They are almost identical in shape to those of megalodon (Great White Shark) although the fossil is plainly not such a beastie.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.megalodonteeth.com%2Fimages%2Fstock%2Fcommlg.jpg&hash=42186d7763df08a65c25746f1722cf14)
image from megalodonteeth.com
-
I am truly amazed at the responses I have gotten so far [;D] This began as a shot in the dark for me and I never anticipated I would recieve so much useful information! DoctorBeaver, JimBob... my sincerest thanks! My son is so fascinated by all of this and is eager to share with his class.
And I'm still open to more info!!
[;)]
I'm glad you're finding this useful. And I'm also glad your son is taking an interest. I bet he now wants to be a paleant paliontol - fossil hunter!
Just 1 point, though. Don't listen to anything the mad Texan JimBob says. He's just a geologist. [:D]
-
Do we now have more old crocs on the forum?
-
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Fangry2%2F11.gif&hash=ef77c6e2d50d42acd17192a634104bfe)
-
If it's a croc, where are the nasal openings? In the image you posted, one is clearly visible at the end of the snout. There is not even a slight indentation on the fossil.
The teeth in your image certainly have the right colouration, but there are no incisor-like teeth in the fossil except for maybe the front pair and another at #3.
Also, look at the bottom of the upper bone in your image and compare it with the fossil. The 1 in your image is like a rollercoaster; totally different from the fossil.
I have to disagree with you about there being no living fish with teeth like those in the fossil. They are almost identical in shape to those of megalodon (Great White Shark) although the fossil is plainly not such a beastie.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.megalodonteeth.com%2Fimages%2Fstock%2Fcommlg.jpg&hash=42186d7763df08a65c25746f1722cf14)
image from megalodonteeth.com
Eth, you know better to bring up a red herring such as these. Shark are cartilaginous fish and have been all the way though the Paleozoic to the present. The cartilage is rarely preserved. The only thing in the fossil record is teeth. There are some very rare shark fossils in dark shales but they are impressions of the body and not a record of the cartilage structure.
No teleost fish I know of have teeth like a sharks.
I'm glad you're finding this useful. And I'm also glad your son is taking an interest. I bet he now wants to be a paleant paliontol - fossil hunter!
Just 1 point, though. Don't listen to anything the mad Texan JimBob says. He's just a geologist. [:D]
This is the respect I get. As soon as the other geologists leaves on a mine evaluation, everyone jumps on me. It isn't fair, it just isn't fair. I am not crasey... barking mad.
OH and yes, that could be an eye socket but that is very speculative.
-
I know it's not a shark, I was merely pointing out that some fish do indeed have teeth like those of the fossil. And don't forget that not all fish are teleosts.
-
This is the respect I get. As soon as the other geologists leaves on a mine evaluation, everyone jumps on me. It isn't fair, it just isn't fair. I am not crasey... barking mad.
AWWW! It's nice to be missed (though you probably missed me like a sore tooth after having it fixed by the dentist). Only here for a day, then off to Alabama to help supervise salvage crews. My project is still on task.
Can't add much here, this is not my area of expertise- but what little I do know would back up JimBob.
-
Thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you
BASS
It is a surly, unruly mob here lately. Even the tame beaver seems to be getting uppity.
-
Hello again & goodbye again, Bass [:D]
-
Can't add much here, this is not my area of expertise- but what little I do know would back up JimBob.
Nepotism!
Bass and JimBob up a tree,
K.I.S.S.I.N.G
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Fkissing1%2F7.gif&hash=18fc34f3f0fd0ad87b8a3c3f7c9546fc)
-
Thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you, thank you
BASS
It is a surly, unruly mob here lately. Even the tame beaver seems to be getting uppity.
Uppity and sarcastic as well.
-
Yes, I can multi-task.
-
You can walk and chew gum at the same time!
That's REMARKABLE!!!
-
Walk & chew beech bark, actually [^]
-
I'll give you the waddle and beech bark. A free pass on me.
-
Free? Did someone say free?
-
A jewish Norman?
-
OY-VAY!