Crocodylians
laelaps | May 21, 2010
A Cuban crocodile (Crocodylus rhombifer), photographed at the National Zoo in Washington, D.C.
Outside of the trash-grubbing black bears I occasionally come across when driving to hikes in northern New Jersey, I never encounter large predators near my home. The imposing carnivores which once roamed the "garden state" were extirpated long ago. This is a very unusual thing. For the majority of the past six million years or so hominins have lived alongside, and have regularly been hunted by, an array of large carnivorous animals, but humans have not been entirely helpless. Rather than a one-…
laelaps | February 3, 2010
A restoration of Titanoboa (foreground) in its natural setting. (By Jason Bourque, image from Wikipedia.)
When I was growing up I used to spend hours poring over the Time/Life series of nature books in my little library, absolutely enthralled by images of strange creatures from all over the world, but one photograph was particularly arresting. A grainy black-and-white double-page spread showed an anaconda that had wrapped its crushing coils around a caiman and a tree, slowly squeezing the life out of the crocodylian. Without any frame of reference for size it was easy to envision the two…
laelaps | August 1, 2009
The skeleton of a black caiman (Melanosuchus niger), photographed at the Smithsonian's National Museum of Natural History. [H/T to Thomas Holtz for the correction.]
laelaps | July 28, 2009
When I was a kid the movie Alligator seemed to be on television almost every other weekend. It was one of the first movies I can remember seeing, although truth be told I probably should not have been allowed to watch it. The pool scene alone was enough to give me nightmares.
For those who have not seen it, the film features an enormous, marauding alligator that grew to such prodigious size by feeding on test animals a biomedical corporation dumped in the sewer. It was a pretty clever explanation for how an ordinary alligator could become so gigantic, but long before Hollywood…
laelaps | July 10, 2009
Life restoration of the head of Armadillosuchus. From Marinho and Carvalho (2009).
When I was trying to come up with a title for this post I almost went with "Armadillosuchus: An armored crocodyliform you wouldn't want to mess with." Obviously I changed my mind. Not only was the title too long, but it was redundant to boot. All crocodyliformes (which includes living crocodylians) are "armored" in that they have little bony plates called osteoderms (primarily on the dorsal, or top, side of their bodies) beneath their scales, which in turn overlay a layer of bony plates called osteoscutes.…
laelaps | March 27, 2008
The skull and mandible of Guarinisuchus.
After the end-Cretaceous extinction, an "empty" world was left to fill up. The non-avian dinosaurs were gone, as were the mosasaurs, ammonites, pterosaurs, and other creatures. Indeed, in marine environments the large Mesozoic predators were eliminated in the extinction event, allowing sharks and crocodiles to evolve and diversify now that they were no longer any mosasaurs patrolling the waters. One such crocodylian that moved into open ecological space was Guarinisuchus munizi, just described in the Proceedings of the Royal Society B.
Although…
laelaps | February 4, 2008
The new crocodylian Montealtosuchus arrudacamposi. [Image source].
Living crocodylians have often been referred to as "living fossils," creatures that have survived "virtually unchanged" for hundreds of millions of years. In truth, crocodylians as we recognize them today (i.e. aquatic ambush predators) first appear in the fossil record during the Jurassic (see comment below), but there was a much wider diversity of crocodylians during past epochs that were just as interesting (and even terrifying) as any dinosaur.* In the Bauru Basin of Brazil, for instance, the remains of at least five…
laelaps | February 1, 2008
The new crocodylian Montealtosuchus arrudacamposi. [Image source].
I guess this one slipped by without getting proper attention. In October of 2007 research described a new genus of species of crocodylian, Montealtosuchus arrudacamposi (pictured above) in the journal Zootaxa. It was a late Cretaceous member of the Peirosauridae found in Bauru Basin, Brazil, although it was only one representative of a larger diversity of crocodylians from the location that also included notosuchids, sphagesaurids, baurusuchids, and trematochampsids. Unfortunately the paper is behind a subscription wall (…
laelaps | January 23, 2008
According to a news item posted on CNN.com yesterday, at least 50 gharials have died due to unknown causes since early December in the area of the Chambal river in India. Pollution and parasites seem to be the main contenders for a culprit, conservation biologists reporting that the livers and kidneys of the dead animals were swollen and seemed to be affected by an unknown parasite, although lead and cadmium were also found in the bodies of the gharials. At present the gharial is listed as critically endangered by the IUCN, and the problems in the Chambal river area are especially worrisome…
laelaps | January 15, 2008
A crocodile (I would assume Crocodylus niloticus) from William Cheselden's Osteographia.
laelaps | November 22, 2007
This is the impressive skull of a Saltwater Crocodile (Crocodylus porosus), the largest living crocodylian. What I find so interesting about the skulls of these animals is that the flesh is so closely attached to the underlying bone, the skulls of crocodylians requiring little imagination to discern what the animal would have looked like in life. While such a fearsome animal may cause us to keep track of how many deaths it is responsible for (the Saltwater Crocodile being the most dangerous to humans), the total number of deaths these animals are responsible for absolutely pales in…
laelaps | November 10, 2007Just in case you didn't get your crocdylian fix today, here's a clip from the documentary "The Crocodile's Revenge" that I stumbled across while on YouTube which I remember watching as a kid;
I haven't seen it in years (and I'm going to have to get a VHS player if I want to), but I recall the program quite vividly, especially since much of the documentary was made up of dramatizations of actual crocodile attacks in Australia (although they were much more well-done than similar reenactments on the Discovery Channel these days). In fact I remember a few attack reconstructions that featured…
laelaps | November 4, 2007
Today's photo comes from the National Zoo in Washington D.C., the only place where I have seen the Gavial (Gavialis gangeticus) in captivity. This crocodylian is one of the most endangered in the world, and the National Zoo has a male and female pair (and I can only assume that the zoo staff hopes the two will breed). The above photograph is the female, males of the species having a bulbous growth or "ghara" on the tip of their snout. Outside of being a signal as to which sex an adult belongs, the ghara is also used in vocalizations the male makes and blowing bubbles during mating displays,…