Deinosuchus

21 05 2007

Sometimes in life, expectations are not always met. Growing up I used to pore over dozens of books depicting old photographs from the American Museum of Natural History, making a mental inventory of all the fossil marvels I had to see. Outside of the dinosaurs (some of which still look very much like they did when Henry Fairfield Osborn was at the museum), I absolutely had to see the enormous reconstructed maw of Carcharodon megalodon and the massive skull of the crocodile Deinosuchus. Perhaps I did see them, but unfortunately all I recall from my early visits were the trip to the fossil halls in a cramped elevator, a museum logo featuring a human skeleton next to the skeleton of a horse, and the immensity of the “Brontosaurus” skeleton in the dim light of the dinosaur halls. Returning many years later, I made sure to take my time through the Hall of Vertebrate Origins, leaving no cladistic nook left unexplored, but alas, the massive C. megalodon jaws had been properly downsized and Deinosuchus was nowhere to be found.

All is not lost, however, as the AMNH has kindly allowed the public access to old museum documents by the likes of Barnum Brown, G.G. Simpson, Edwin Colbert, Henry Fairfield Osborn, and many others, and one 1954 publication allows me a look at the giant crocodilian I never had a chance to meet in person. Entitled “A Gigantic Crocodile from the Upper Cretaceous Beds of Texas” (by Edwin Colbert and Roland Bird from the November 12, 1954 edition of American Museum Novitiates), the paper describes a “new species” dubbed Phobosuchus riograndensis. We now know that the genus Phobosuchus riograndensis = Deinosuchus riograndensis (the type species for the genus is Deinosuchus hatcheri), and so the paper serves our interests here just fine.

Deinosuchus
The restored skull of Deinosuchus from the Colbert/Bird paper. Note the darker areas, which are the actual fossil material used in the reconstruction.

While the reconstructed skull is impressive in and of itself, it becomes even moreso when we can see its size relative to some AMNH scientists;

Deinosuchus and scientists
The restored skull of Deinosuchus, featuring (left to right) B. Brown, R. T. Bird and E. M. Schlaikjer [ref: “How the ‘terror crocodile’ grew so big” by Erickson and Brochu, Nature 398, 205-206 (18 March 1999)]

Given that a complete (or reasonably complete) skeleton of Deinosuchus has yet to be found, we can only estimate how large it was from the material at hand, likely 10-12 meters long when fully grown. But how did they get so big? It’s not easy to attain such large sizes, and it’s important to know whether huge crocodilians followed a growth curve similar to that of their living relatives or were instead fast-growing like some dinosaurs. According to this 1999 Nature correspondance by Erickson and Brochu [“How the ‘terror crocodile’ grew so big” Nature 398, 205-206 (18 March 1999)], it appears that Deinosuchus followed the standard grow-throughout-life pattern exhibited in its modern relatives, perhaps taking upwards of 35 years to fully attain the monstrous sizes we’re familiar with. Given that many extant crocodilians do not live long enough to reach maximum size, perhaps the largest individuals would be more rare than smaller ones, although I am not familiar enough with what has been recovered from these animals to prove or disprove such an idea. While I’m on the subject, of course, Darren Naish has a great post (just posted yesterday, as a matter of fact) involving giant crocodylians, so be sure check his writing out as well.

As for the fossil material discussed in the Colbert/Bird paper, here is what was recovered;

TYPE: A.M.N.H. No. 3073. Almost complete premaxillae and part of a right maxilla, portions of left articular, angular, and surangular, right and left dentaries and right and left splenials; one dorsal vertebra, probably the twelfth vertebra of the presacral series; right scapula, possible portion of a right ilium; scutes and other fragments.

For an animal Colbert and Bird estimated to be up to 50 feet long (6 feet of which being skull), not very much was left over. The reconstructed skull itself belies this, the very front of the jaws and the very back of the lower jaw making up most of the skull material, the skull as a whole being based upon the notoriously bad-tempered Cuban crocodile (http://en.wikipedia.org/wiki/Crocodylus_rhombifer). Colbert and Bird did argue, however, that their fragmentary crocodilian could be even longer than 50 feet in length because they the cuban crocodile had a more blunt snout, and if they had based the reconstruction on the Saltwater Crocodile (Crocodylus porosus) and American Crocodile (Crocodylus acutus) (which have comparatively longer snouts), the size estimate for their specimen would increase further.

It would be wonderful if I could now go on to describe Deinosuchus as we now know it, but (outside of a decrease in size) it doesn’t seem to be very different from the way it is depicted in the Colbert/Bird paper; as the Cretaceous equivalent of the modern-day alligator. Perhaps someday some more skeletal material will help us further flesh out this animal, but the lack of material hasn’t stopped it from becoming a “fan favorite” of paleontology; it often shows up along dinosaurs in model sets, books, and television shows. A more complete crocodilian is the famous Sarcosuchus imperator (and if you haven’t already seen it, check out National Geographic’s documentary SuperCroc),but hopefully more fossils from other giant crocodilians will be discovered so that some comparisons can be made among the giants.

While today New Jersey is usually free of alligators and crocodiles (I say usually because every now and then a release “pet” shows up), this was not always the case. Just in the past year, one of the most well-preserved Thoracosaurus neocesariensis skeletons was extracted from the green marl (stuff gets everywhere, let me tell you) of the Inversand pit in Gloucster County, New Jersey, by Drexel University students and Dr. William Gallagher of the State Museum in Trenton. You can have a look at the recovered material via Drexel’s website here, read a Philadelphia Enquirer article about the discovery here, see an early artistic depiction by Cope at the HMNH, or see a more recent depiction by Dan Varner at Oceans of Kansas.

When I was at the pit last fall, I found a croc scute, but there are several species of crocodilian known from the pit and I could not discern to which it belonged to. I also checked out the location from which Dr. Gallagher found the Drexel Thoracosaurus, but there didn’t seem to be any lingering fossils either, so I focused on trying to extract some bone from a spot that was bearing well in the Main Fossiliferous Layer. The bone was beige on top, dark brown in the middle, but came out only in fragments and I could not tell what I had found. Hopefully when I return on Wednesday I’ll be in luck, and you can expect a post all about what I find on Wednesday.

Advertisements




Photos from the National Zoo; Pandas, Wolves, Gharials, and More!

15 04 2007

Looking back, Saturday seems like a dream. I’m sure part of that is due to the fact that I only slept 2 and 1/2 hours before getting up at 2 AM to drive to the National Zoo in Washington D.C. and spend the day with my wife and her parents. Lack of sleep aside, never have I been to a zoo with such wide species diversity, and while I still consider the Bronx Zoo to be the best I’ve ever been to, I was absolutely amazed by many of the residents of the National Zoo.

My wife and I arrived at 6:30 AM, hoping to see most of the animals in the zoo while they were still active. Unfortunately, most of the animals don’t make an appearance until later in the morning and the various houses didn’t open until 8:30 and 10:00 AM, so other than the occassional jogger there wasn’t much to see. Up in a tree, however, were two Red Pandas sleeping in, and here’s one of them in the early-morning light;

Red Pandas

A Mara, in contrast to the sleeping Red Pandas, was up and about;

Mara

Around the time that my in-laws arrived more of the animals were out on display, although before proceeding my wife wanted a picture of us together next to a statue of a sloth bear. Here it is, both of us looking rather unsettled because the sun was in our eyes and we were trying to communicate how to work my camera;

Us

One of my most favorite animals from the zoo was the Maned Wolf, although unfortunately their enclosure didn’t allow me to photograph them without a doghouse or chain fence in the background;

Maned Wolf

The miniscule Tammar Wallabies were also a highlight. Despite my appreciation for wildlife, every time I see them something in my head goes “Aww, whosanitsybitsy then?”

Tammar Wallaby

We also saw a rather old Spectacled Bear, and for some reason this particular one reminded me of Jeremy Irons. In any case, I have never seen one with an overall blond face (normally they have blond lines/patches that make them appear “spectacled”);

Spectacled Bear

I also finally got to see a Caracal in the flesh, although this was one angry cat. Frustrated that it couldn’t visit it’s other enclosure or get the birds on the outside, it wasn’t too happy when I stooped down to take its picture;

Caracal

Several cheetahs were also on display, a male desperately seeking the affection of this young female (although they were separated by a fence);

cheetah

I also got to see two 10-month old Bengal Tigers at the zoo, although their enclosure wasn’t exactly condusive to good photography. Here’s one of them after making an attempt to snag a bird that entered the enclosure;

Young Tiger

Speaking of young animals, two young sea lions were playing “king of the rock” in their enclosure;

Sea Lions

Two young otter brothers were also a bit scrappy, chasing each other about their enclosure and taking dirt/pine needle baths;

Otter

Other small mammals were also active during our visit, including a Banded Mongoose and some Meerkats;

Mongoose

Meerkats

Some of the local fauna proved to be just as interesting as the exotics; we spotted two white-tailed deer in the zoo as well as this small bird that had collected a flamingo feather for its nest;

Bird

I also finally obtained a photograph of one of my favorite animals, the Giant Elephant Shrew;

Elephant Shrew

While I am absolutely enthralled by mammals, I was also overjoyed to see a male and female Gharial up close in the Reptile House. Here’s the female, just before slipping into the water to join the male;

Gharial

The Great Ape House also provided for some good photographic opportunities, especially some young gorillas and an oranguatan that used some cardboard as a sun hat. In fact, many of the orangs at the zoo seemed to like cardboard as a hat, blanket, etc., which I had never seen before.

Gorilla

Oranguatan

Speaking of primates, this small tree shrew in the Small Mammal House slowed down long enough for me to get a good picture of it. Just seeing how it handled its food and used its hands left no doubt in my mind that primates are derived from such creatures;

Tree Shrew

I also encountered an animal I had never heard of before; the African Pygmy Falcon.

Pygmy Falcon

A Mouse Deer also made a brief appearance during our visit;

Mouse Deer

But what about the Giant Pandas? Well I was able to shoulder my way through the crowd of photographers and snag plenty of pictures of the young panda residing at the zoo;

Panda Sit

Panda Log

Panda Tree

Panda

While the young panda was certainly cute and very entertaining (i.e. watching a panda scale a tree for a good scratch), my most favorite moment from Saturday involved a female Mexican Wolf (a subspecies of Grey Wolf). When I arrived at the enclosure the three females were pacing back and forth near the back of their enclosure, stopping every now and then to look at my wife and I. There was no way I was going to get a good picture, but I discovered the cage was connected to another one the wolves could access, and after waiting a moment one of them came over to the front for a drink. After lapping up some water she took a long look at me and rejoined her pack, and here’s my favorite picture that resulted from my stroke of luck;

Wolf

While the 4 hour drive each way wasn’t very fun, I did highly enjoy myself at the zoo and hope to return soon. Even so, I would love to see these animals in the wild someday. While I certainly have some ok pictures, there’s not much of a story to them; “I walked by the enclosure and the wolf looked at me,” isn’t an experience that’s earned. Granted, in the wild I would get nowhere near as close to these animals nor be able to get them to “pose” for me, but I would much rather catch a fleeting glimpse of a wolf or jaguar than know they only exist in zoos and memories.





Photo of the Day: Dwarf Caiman

24 03 2007

I love getting water-level shots of crocodilians; here’s one of a dwarf caiman at the Bronx Zoo.

Dearf Caiman

Although it’s neat to see all the different snakes and turtles, I’ve always been a little ambivalent about Reptile Houses in general. There typically isn’t much space, so lots of snakes and lizards and caimans are cramped into small displays. Granted, some things are content just to sit under their heat lamp and not do very much and during the winter the animals have to be inside, but I wish there was a way to give them a bit more space.





Extinct and Extant Crocs in the News

21 03 2007

Apparently it’s a good day for Crocodilians, LiveScience heralding the discovery of an extinct crocodile in Oregon and the news of American Crocodiles being taken off the endangered species list. The extinct crocodile, belonging to the genus Thalattosuchia, is the oldest ever recovered in Oregon and belongs to a group that seem to show a transition from being semi-aquatic to fully-aquatic, although I have yet to see any pictures of the actual skeleton myself. Overall the article was a bit light on substance, but if your interest in big extinct crocodilians has been stoked, check out this post at Tetrapod Zoology.

As for the other story, when I was young I remember alligators being endangered, but now their population (thanks to lots of canals and waterways connecting the suburbs) their populations have exploded, something brining them too close for comfort with people;

alligator

As I recall, the American Crocodile (Crocodylus acutus) was in even more dire straits, but as of yesterday they have been taken off the endangered species list as their current population in America has reached over 2,000 (up from about 300 in the 1970’s). Why the population increase? Well, other than protection they received facilities like nuclear power plants significantly warmed up the water in certain areas, making such habitats more welcoming to the crocodiles. This phenomenon is actually readily observable in my own state as well, being that if you seine net in a bay near a nuclear power plant you will catch some tropical species that seem like they’d be more at home on a coral reef than at the Jersey Shore. What I’m curious about, however, is the intersection between alligators and the more aggressive crocodiles as croc numbers go up, as well as interactions with people. The wikipedia entry for the American Crocodile features a photo of a croc at Sanibel Island, Florida, the same place that had to change their alligator size-limit policy after a rash of attacks occurred a few years ago. Either way, you now have two species of related large reptilian predators living in the same habitat, one far more aggressive than the other; studying their interactions could prove to be very illuminating, and I would do it myself if I only lived in Florida.

American Croc





Mesozoic monsters

16 03 2007

Darren Naish over at Tetrapod Zoology has a fantastic post about Mesozoic Crocodilians, debunking the idea that dinosaurs were the only significant predators of the time. I’ve always been enthralled by the varied crocodilians that existed during the same time as the dinosaurs, Deinosuchus being my most favorite as a child (I had a book that showed the huge skull at the American Museum of Natural History, but I never got to see it in person).





Thank you

10 02 2007

I’ve been blogging here on WordPress for less than two months, but the response I’ve gotten so far has been wonderful; in the time I’ve been posting here I’ve received 1,124 visits (at the time of this entry), and while this number may seem paltry I am glad so many people have been enjoying my writing. As a bit of a “celebration,” I’ve posted some pictures from my last trip to the Bronx Zoo a week ago, and I would also like to say “thank you” to the people/blogs who’ve linked to me in the past week, giving a huge boost to my stats. Randy Olson, Ed Brayton, and Pim van Meurs all linked to my ramblings on the “Hoax of Dodos” post from a few days ago, and I also wanted to thank Daniel at Migrations and Felix at OceanicDreams for the addition of my blog to their blogrolls. When I first started writing I didn’t know if anyone would care what I had to say, and while I may not be in the “big leagues” yet, I definitely appreciate everyone who has a look at what I have to say. On to the pictures!

WCS Polar Bear

Bird

I don’t know what kind of bird this is (I forgot to write it down), anyone know?

Dwarf Caiman

I always wanted to get a shot like this one, the “eyes above water” deal, and this Dwarf Caiman gave me the perfect setup.

Fish in the Tiger Pool

These are some of the fish in the pool in the Tiger Mountain exhibit; the tigers don’t eat them.

George

George the lion was pretty aggravated I was around last weekend, making the long distance communication calls (waaaaaoooooooooo-wwaaaaaaoooo-huh-huh-huh-huh-huh) the whole time I was there.

Snow Leopard

The mother of twins, this mother Snow Leopard took some time to enjoy a bone.

Matamata

Another creature that I usually can’t get a shot of; the Matamata turtle.

Ptth!

Yawn

This is Zeff, a 13-year old female tiger at the zoo. Although she seems to be snarling, this was actually the end of a yawn, but I like how it came out nonetheless.

Sasha and his tree

Although it’s not the best shot I’ve ever taken, I love this picture of Sasha (a young male Amur tiger kept next to Zeff) rearing up to scratch the tree.

Spoonbill

This spoonbill flew out of its enclosure and rested on the rail, setting it up for a decent shot.

Snow Leopard Twin

One of the snow leopard twins born a few months ago.

Zeff walking by

Zeff staring





Some monsters are real

26 01 2007

Last night my wife and I got to have a little Mystery Science Theater 3000-type viewing of the recently released stinkbomb, Primeval, as we were the only two people in the theater (the only other people in the theater left about 1/3 of the way through). I grew up watching bad movies, films like Alligator (written by John Sayles, no less) being among my favorites (see Orca, Tentacles, Piranha, Prophecy, THEM!, Frogs, Grizzly, etc. for more examples) and almost always on TV every other month or so via TNT/Sci-Fi/TBS/FOX. Come to think of it, I spent a good deal of my childhood watching monster movies (begging my parents to stay up late), playing with my Legos and trying not to think about the weird noises in the night that became all-too-abundant after the film ended. I never really grew out of the phase, seeking out real life monsters rather than giving them up, and I still love anything that has to do with dinosaurs, sharks, crocodiles, or man-eating monsters born via radioactive sludge in films, expecting nothing much and having a good time ripping on the bad production values. If it gives you any indication of the quality of the movie, Primeval gave my wife and I plenty of material to riff on.

Before I go any further, I do want to say thank you to my wife for coming along with me to the film, indulging my boyish tendency to go out and watch monster movies even though I know they’re going to be utterly appalling. As she commented after we left the theater, she was surprised Primveal got a theatrical release, the special effects just a step above horrid Sci-Fi Channel original movies like Mammoth (the worst movie I have EVER seen, EVER!) and Attack of the Sabertooth. Indeed, during the first nighttime appearance of the films killer crocodile, it looked like it was a CGI-version of the old stop-motion animation style of Willis O’Brien or Ray Harryhausen, exaggerated and fast movements of the featured creature in order to make it seem more “lifelike.” Even when we got to see the croc in full daylight, the CGI paled in comparison to what could have been achieved with puppets, and giving it an endless supply of stamina as it awkwardly galloped after Orlando Jones was incredibly silly. Granted, crocodiles look silly when they “gallop” anyway, but whoever did the biomechanics research for this movie obviously has never seen a fast-moving crocodilian. I really don’t understand why move companies put so much into crappy CGI-rendered monsters when puppets look better and add to the realism of the film; the sharks in the film Deep Blue Sea looked great as puppets but horrid as CGI-rendered monsters. There’s plenty of gore in the film as well, but usually it’s so dark it’s hard to make out what exactly is being ripped apart (except at the end when the crocodile pops the main human antagonists head like a grape), and in classic movie-monster style it knows how to take out underwater supports of a pier in order to get at the humans, it literally sniffs out the bad guy at the end, it eats a soldier about to rape a woman, it has an endless amount of energy & cunning, so really nothing like a real crocodile at all. What is more frightening to me are the real animals, the ones that are so swift, deadly, and quiet that you often attacks are little more than someone bathing never to you and then they’re suddenly gone in a swirl of water. Such is an account in the car-wreck of a coffee table book The Eyelids of Morning, in which a young man was standing on a rock in a body of water and then he suddenly wasn’t there, appearing a short way downriver in the jaws of a Nile Crocodile, which later was caught and the young man’s legs were extracted from the crocs stomach (framed in a blood-spattered cardboard box in the book). Such events are enough to keep me out of Africa’s rivers, lakes, and streams.

Primeval would have been bad enough if it was simply concocted by a group of executives who decided that Lake Placid was a great work of cinema, but it’s actually loosely inspired by a real killer crocodile named Gustave (named by Burundians for a ruthless president during civil war). Studied almost exclusively by Patrice Faye, a French self-proclaimed naturalist, Gustave lives in the waterways of Burundi, especially Lake Tanganyika and Rusizi River, reportedly reaching a length of 20 feet and weighing a ton (suggesting he has long surpassed the average 45-year longevity of most Nile Crocodiles). Such a large crocodile is enough to make people afraid by merit of its size alone, but Gustave has been charged with over 200 human deaths (as well as one adult hippo), the body count going ever-higher.

Gustave

The above picture is one of the few I’ve seen of Gustave, the few pictures floating around on the internet not having much for scale in the pictures and most of the pictures Faye has taken have not made it to public viewing, apparently. While on assignment to track down the killer croc, the National Geographic team dispatched never found Gustave, and there has been little to no news about the whereabouts of the creature since 2005. The National Geographic article about the expedition has an editor’s note update, suggesting that Gustave has not been seen since at least November of 2006 (the rainy season making it difficult to track him), although 10 more deaths have been added to the list of fatalities. There is little doubt that Gustave has killed many people, but many remain skeptical of his legendary appetite for human flesh, seeming more like a catch-all explanation whenever anyone goes missing or gets taken by any crocodile. Indeed, how can you tell the size (or identity) of a crocodile when they are underwater? The one characteristic that seems to confirm the genuine attacks from other incidents is the fact that Gustave bears a dark scar on his head, something that is independently confirmed by those who get a good look at him during attacks. We know crocodiles kill and eat many people in various parts of the world every year (there’s no such thing as a “man-eating crocodile” because at least for saltwater and Nile crocodiles, they all have the propensity to do it if the opportunity arises), and it’s easy to believe that a crocodile of such gargantuan size would have an appetite to match, but there seems to be little actual evidence to back this up. Indeed, I haven’t seen any official reports made, books published, or other scientific discussions of case studies for those supposedly killed by Gustave (as is done with shark attacks via the Global Shark Attack File) and Faye doesn’t seem in much of a hurry to get empirical data out to the scientific community at large. Sure, everyone knows of Gustave and would like to catch him for study, but he has become more of a living legend to be captured/exploited than an actual animal to be studied. If Gustave is anything like the mythology makes him out to be, such a case study would be very illuminating from the perspective of ethology and human/ecological interactions, but it seems that the few scientists who have gone there have been so enthralled with trying to catch Leviathan for the cameras that all other empirical study doesn’t mean very much. I don’t mean this as a put-down to people like Brady Barr (the scientist who went with National Geographic), but what if we took the focus off trying to catch the animal and instead tried to figure out what the role of such a huge animal is in an ecosystem and what he is eating.

I don’t know if the mystery of Gustave will ever be fully solved, and it is likely that his story will fade away into obscurity over time. In places that are impoverished and torn by war, who has time to think about monsters in their own backyard? Once such places become developed, then all that was once wild is either tamed or exterminated, so either way Gustave seems more like a remnant of the mystery and danger Africa used to represent when it was still (dubiously) known as the “Dark Continent,” and because such mystery and the Jungian need to still have monsters in today’s world, I don’t think we’re ever going to know as much as we should about such a magnificent animal.