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The Prehistoric Croc Thread- Anything crocodilian related

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  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    National Geographic's headline of 'Biggest Crocodile Found' made me think we were getting another 40+ footer :(
    http://news.nationalgeographic.com/news/2012/05/120508-biggest-crocodile-early-humans-science-animals/


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Galvasean wrote: »
    National Geographic's headline of 'Biggest Crocodile Found' made me think we were getting another 40+ footer :(
    http://news.nationalgeographic.com/news/2012/05/120508-biggest-crocodile-early-humans-science-animals/

    It's a very interesting discovery, tho. Now it seems that the modern day Nile crocodile didn´t appear until after these big guys (C.thorbjarnarsoni and C. anthropophagus) dissappeared... plus the fact that the Nile crocodile seems to be more closely related to American crocodiles than to any of those ancient giants (or to modern day sacred crocodiles Crocodylus suchus which was actually believed to be the same as the Nile croc!) seems to indicate that Nile crocodile ancestors swam from the New World to Africa and took over the niche left vacant by the native giants!


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    Not so sure about intercontinental swimming migration en-mass. I'd say more likely their ancestor already lived there (albeit in smaller form).


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Not a new creature, but a study confirming that the awesome Dakosaurus, a marine "crocodile" that looked rather like a cross between a theropod and a shark, was perfectly adapted to hunt and eat large sea reptiles- perhaps larger than itself.
    The study shows that the teeth of Dakosaurus would interlock when it closed its jaws, and this would cause a shearing effect, allowing the "croc" to slice large chunks of flesh from a carcass (or live prey?) more like a great white shark than a crocodile.

    http://onlinelibrary.wiley.com/doi/10.1002/ar.22491/abstract
    dakosaurus2.jpg

    Dakosaurus_1.jpg


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    I still think Dakosaurus is a theropod dinosaur that evolved to live in the sea...


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  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Believed to have been 8-12 meters long or so, the creature belongs to already known genus Pallimnarchus, but was much bigger than any previous specimen found. It may represent a new species.

    http://www.heraldsun.com.au/news/national/croc-and-awe-over-dino-mite-fossil/story-fndo45r1-1226442903133
    930393-bok-khoo.jpg


  • Registered Users Posts: 8,551 Rubecula


    There have been so many mega crocs in the past it makes me wonder when the next one will evolve.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Im pretty sure we would have some super crocs today if they were left alone and allowed to grow to their maximum size :(


  • Registered Users Posts: 25,560 ✭✭✭✭ Kess73


    Adam Khor wrote: »
    Im pretty sure we would have some super crocs today if they were left alone and allowed to grow to their maximum size :(



    Yep Salties have shown over the past 30 or so years that their average sizes, in areas were they are left be, increase to a sizeable degree. Even the maximum accepted size of Salties has increased in the last decade or so as larger live specimens to what were found in the past appear.


    If we look again at the last few decades, the largest maximum size that I just mentioned has actually increased by between a half metre to a full metre with the 7m range now being seen the maximum size much as the 6m range was in the past. Who is to say that with another few decades of unhindered habitats that the 8m range may not replace the 7m one.


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    Pleistocene eh? Reasonable chance it may have munched a few people so.


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  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    Rubecula wrote: »
    There have been so many mega crocs in the past it makes me wonder when the next one will evolve.

    I'd say it will be quite some time (if at all) before we get another crocodilian that gets to the 10meter+ cut off point usually associated with 'super crocs'. A population of super crocs needs a surplus of very large prey. Generally for the prey items to grow so large en-mass there would need to be more 'room for expansion', ie: larger consistent habitats for them to live in. Currently most habitats are getting smaller due to manmade interference, limiting the opportunity for much land based or semi-aquatic gigantism.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Galvasean wrote: »
    I'd say it will be quite some time (if at all) before we get another crocodilian that gets to the 10meter+ cut off point usually associated with 'super crocs'. A population of super crocs needs a surplus of very large prey. Generally for the prey items to grow so large en-mass there would need to be more 'room for expansion', ie: larger consistent habitats for them to live in. Currently most habitats are getting smaller due to manmade interference, limiting the opportunity for much land based or semi-aquatic gigantism.

    Unless some saltwater tolerant crocodiles moved to the sea and became true marine animals :D

    Ok no :(


  • Registered Users Posts: 8,551 Rubecula


    Adam Khor wrote: »
    Unless some saltwater tolerant crocodiles moved to the sea and became true marine animals :D

    Ok no :(
    Cue a megalodon sized croc?

    It could happen that crocs become more marine orientated but that would take a huge amount of time by our reckoning. (A mere blip to geological time of course) I would think that either a big stable river system or a vast lake/inland sea with mega fauna living around the boundaries.


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    Hey, it nearly worked for the spinosaurids...
    That said though, every time the crocs attempted to become purely aquatic down through the years their success was somewhat limited.

    Metriorhynchus_closeup.jpg


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Galvasean wrote: »
    Hey, it nearly worked for the spinosaurids...
    That said though, every time the crocs attempted to become purely aquatic down through the years their success was somewhat limited.

    I wouldn´t say sea croc success was limited... they lasted from the middle Jurassic to the Cretaceous, they were found all around the world, and the most derived ones seemingly spent their entire lives in the sea, probably giving birth to live young. As if that wasn´t enough, they gave rise to creatures as huge as Machimosaurus (11 meters or so) and as un-croc-like as Dakosaurus, basically the reptilian version of a great white shark. I'd say they were quite succesful really. :cool:


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    11 meters!?!? Why the heck isn't Machimosaurus more famous? I had to look it up just now!


  • Registered Users Posts: 8,551 Rubecula


    And I had to look up the Dakosaurus :mad:

    I am ashamed, a marine reptile I never knew about.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Bigger than Dakosaurus, at about 7 meters long, but smaller than Machimosaurus, although better adapted to a marine lifestyle.

    http://www.nhm.ac.uk/about-us/news/2012/september/ancient-crocodiles-ate-like-killer-whales114204.html

    Creatures like this make me happy.

    crocodylian-size-470-114226-1.jpg

    crocodylian-size-490_114203_2.jpg


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    I guess we can ad suction feeding to the rapidly growing list of feeding techniques employed by crocodilians down through the ages.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Was found in Spain so I'm translating the good parts as usual:

    Researchers from the universities of Zaragoza and Edinburghhave described another sea crocodile of the Jurassic, found in Ricla (Zaragoza), which coexisted with dinosaurs. Maledictosuchus riclaensis (Ricla's cursed crocodile) is the oldest and best preserved sea crocodile found in the Iberian peninsula.
    ...
    The researches have noted that Maledictosuchus is known only through the specimen from Ricla, and is a practically perfect skull, excepcionally well preserved.
    The specimen belongs to Metrorhynchidae, a group of sea crocodiles typical of the Jurassic which went extinct during the early Cretaceous, about 130 million years ago, having coexisted with dinosaurs.
    The fossil was found in 1994 during the (...) building of the AVE railroad. This crocodile inhabited the seas 164 million years ago during the Middle Jurassic (Callovian).

    The skull of Maledictosuchus is streamlined, with huge eye sockets and very small, numerous teeth. It was mostly a fish-eater, although it may have eaten cephalopods and other sea invertebrates. The research suggests that Maledictosuchus is the basalmost and oldest member of the rhacheosaurines, a group of specialized metriorhynchids, fish-eaters, very well adapted to the open sea. Therefore, the study of this last crocodile proves that metriorhynchids were more diverse than previously thought and that their adaptation to life in the open sea started during the Middle Jurassic, 10 million years before the accepted date

    Well, it seems we are in a sort of golden age of sea-crocodile discoveries :O

    maledictosuchus-riclaensis-craneo-estudio.jpg

    CocoRicla2.jpg


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  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Two new crocodilians found in Panama appear to be transitional between gators and caimans:

    http://www.livescience.com/27613-crocodilian-species-fill-fossil-gap.html
    n1FFXHD97umSi84b.jpg


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 87,132 Mod ✭✭✭✭ Capt'n Midnight


    could they have rafted over ?
    crocs can live a long time without food


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    could they have rafted over ?
    crocs can live a long time without food

    The thought did cross my mind... then again, Deinosuchus was an alligatoroid (more caiman or gator than crocodile) and it was seemingly able to live in saltwater, so maybe we shouldn´t rule out the possibility that these guys were able too...


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




  • Registered Users Posts: 8,551 Rubecula


    Just to give an idea of the size of these beasts:

    The saltwater crocodile (Crocodylus porosus), also known as saltie, estuarine or Indo-Pacific crocodile, is the largest of all living reptiles, as well as the largest terrestrial and riparian predator in the world. The males of this species can reach sizes of up to 6.7 m (22 ft)[2] and weigh as much as 2,000 kg (4,400 lb)

    However, an adult male saltwater crocodile is generally between 4.3 and 5.2 m (14 and 17 ft) in length and weighs 400–1,000 kg (880–2,200 lb), rarely growing larger


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    There's a fourth species, Machimosaurus rex; it's from the early Cretaceous of Tunisia, being the last known teleosaurid as well as the biggest known thus far:

    http://www.sciencedirect.com/science/article/pii/S0195667115301178

    1-s2.0-S0195667115301178-fx1.jpg


  • Registered Users Posts: 8,551 Rubecula


    I was about to post this too lol


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




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  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




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