jump to navigation

New Apex Predator Theropod Dino Species Discovered November 29, 2013

Posted by intellectualgridiron in Science.
Tags: , , , , , , , , , , , , , ,
add a comment

siats-meekerorum-dinosaurPaleontologists announced a major discovery in Paris recently, that of a new species of apex Theropod predator found in North America.   At over 30 feet long and weighing 4 tons, It was one of the greatest land predators on Earth when it lived 100 million years ago.  Scientists found the fossilized remains sticking out from a slope in the Cedar Mountain Formation of Utah in 2008.  It would take two years to slowly remove them from the rocks and cleaned, and two more to analyze the bones to see if in fact this were a new species not yet in the scientific/fossil record, etc.  Scientists named it Siats meekerorum; the genus honors the mythical, cannibalistic monster from Ute tribal lore (the genus name is pronounced “SEE-atch”).

The fact that a new 30-foot Theropod has been discovered is amazing news enough.  But what is even more amazing is that this is the first predatory dino species this size to be discovered in North America in more than six decades.

“It’s been 63 years since a predator of this size has been named from North America,” said Lindsay Zanno, of North Carolina’s State University and Museum of Natural Sciences, in a press release.

“This dinosaur was a colossal predator, second only to the great T. rex and perhaps Acrocanthosaurus in the North American fossil record,” Zanno continued.

Even more significant is that the discovery of a predatory species this size fills in a 30 million-year gap between the extinction of Allosaurs and the maturation of the evolution of the Tyrannosaurs in North America.  True, Carcharodontosaurus was a major predator at this time, too, but the current fossil record indicates it was only around from 100-93 million years ago — much more narrow span of time.  Moreover, its fossils have been found in what used to be the supercontinent Gondwana (specifically, present-day Africa and South America).  The aforementioned Acrocathosaurus was in the same taxonomical family as C. saharicus, and it was found in North America, but its known span of existence, according to current fossil records, was about 116-110 million years ago.

The discovery of this species has shed new light as to which species sat atop of the proverbial pyramid in this given ecosystem in North America some 98 million years ago.  The Tyrannosaurids that did exist at this time were much smaller.  The extinction of Acrocanthosaurus first, and later Siats meekororum dying out, eventually opened up the opportunity for Tyrannosaurids to grow larger into the T-rex that we all know and love today.

Buicks and Dinosaurs March 28, 2013

Posted by intellectualgridiron in Pop Culture, Science.
Tags: , , , , , , , , , , , , , , , , , , , , , , , ,
add a comment

As a life-long Paleontology enthusiast, I feel compelled to give General Motors lots of credit for this creative commercial.  Remember that comic book and cartoon series “Cadillacs and Dinosaurs”?  Well, feast your eyes on the next-best thing:  Buicks and dinosaurs!

What caught my eye the first time I saw this commercial was not just the dinosaurs, but their species and size.  Yeah, they were big – really big, but just how big?  It obviously varies from genus/species to genus/species, but what interested yours truly was their depicted size in the commercial.  We science/engineering geeks are sticklers for accuracy, after all!

Start with the beginning.  The Stegosaurs parked next to the fire hydrant are accurate.  Stegosaurus armatus, for example, reached about 30 feet in maximum length, meaning that its likeness regarding shape and size in the commercial is well portrayed (S. stenops was not quite as long at 23 feet in max. length).  So far, so good!

At seconds 6 through 13, we feast our eyes on a massive Sauropod, massive even by the standards of the already-large species found within the infraorder.  My first guess was this was an outsized specimen of Apatosaurus (known by many as “Brontosaurus,”) which was indeed large at an average length of 75 feet.  But as big as it was, it is doubtful that its feet were almost as wide as the car itself, even if the Buick Encore is relatively small.  The photo below of a Apatosaur skeleton right next to a Diplodocus skeleton might give the reader a better reference of its average size, as one can see a couple of people standing behind it.

ApatosaursDiplodocus1

Apatosaurus in the near background, and Diplodocus in the foreground at the Carnegie Museum of Natural History in Pittsburgh; photo by author, Dec., 2010.

My guess regarding the large Sauropod depicted in the commercial in question is either an outsized specimen of Apatosaur (it was the overall shape of one, if not oversized), or, more plausibly, an Argentinosaurus, one of the largest dino species currently known to man.  This compilation of photos I snapped at the Fernbank Museum in Atlanta back in early 2009 should back up the validity of this educated guess.  The man ascending the staircase gives the reader an idea of its huge size.

ArgentinosaurusCompilation1

Argentinosaurus reconstructed as being pursued by a Giganotosaurus, a Carnosaur/Theropod even longer than T-rex! Photo by author, Fernbank Museum, Atlanta, Mar. 1, 2009.

Next up at seconds 14 through 16, the couple in the Encore are passing up a couple of Ceratopsians.  The initial impulse is to say “Triceratops,” which is entirely understood, given that he was the biggest and most famous of that suborder.  But the frills of these two fellows are way too squared for that to be Triceratops, so my educated guess is that these are slightly outsized Chasmosaurs, who also had three horns like their slightly larger cousin (most Ceratopsians just had one, on the nose), even though theirs were not as long as the larger species.

Meanwhile (“…back in the jungle!”), as the camera gives us the vantage point of seeing through the windshield from the backseat, we see more Stegosaurs and Sauropods moving along the boulevard during seconds 17 through 19, and then the car has to maneuver around another large Sauropod (possibly a slightly-outsized Apatosaur, if not another Argentinosaur), before eventually pulling into a hotel entrance next to another Stegosaur to cap off the commercial.  Here the Stegosaurs is depicted a bit larger than its maximum size, unless the roof in front of the hotel desk had a very low clearance of 13 feet or less, as that was S. armatus’ maximum height, plates included.  The Stego tail and spikes in the background during seconds 27 through 29, however, are sadly way oversized.  The spikes in question would reach about three feet at the most.

Something else that gave cause for notice is that all the dino species depicted in this GM commercial are plant eaters.  So what, right?  The significance of this selection of species was that these are thought by many – though by no means all – scientists to be cold-blooded, or at least homoethermic, whereby they were big enough to maintain their own temperatures.  But put these two things together, and these species would be, on average, on the slower scale of dino agility, particularly when compared to their potentially hot-blooded Theropod predators.*  What it boils down to is a  “big-and-slow” versus “small-and-nimble” comparison that GM implicitly makes in this advertisement.

One must analyze these sizes with the perspective that these are all computer-generated, and as such, when superimposed into a real-world setting, it’s difficult to get the relative size proportions correct, especially when these objects are in constant motions and audience viewing angles are constantly shifting.  Still, while most shown sizes are a tad exaggerated, some were dead-on, and overall, the effort is quite laudable, as the commercial certainly piqued my interest, and hopefully those of millions of other viewers!

*The cold-blooded/warm-blooded dinosaur debate has been brought up before in a previous article and shall surely be revisited again.

Dinosaurs were warm-blooded, scientific paper reports January 29, 2013

Posted by intellectualgridiron in Science.
Tags: , , , , , , , , , , , , , , , , , , ,
1 comment so far
Allosaurus_side1

Another scientific paper offers convincing evidence that (at least some) dinosaurs were warm-blooded, such as this Allosaurs, but what of the Apatosaurus whose tail is also visible in this picture? Photo by the author, taken at the Carnegie Museum of Natural History in Pittsburgh.

The dinosaurs were warm-blooded, so reports a recently-published scientific paper.  To that, those of us who have paid any serious attention to dinosaurs over the past 25+ years, we reply in one big voice, “well, duh!”

But believe it or not, there has been a four-decade debate as to whether or not dinosaurs were ectothermic (i.e., cold-blooded) like all reptiles today, or endothermic (i.e., warm-blooded) like birds and mammals.  It was not always that way; even most of the earliest dinosaur fossils discovered roughly 190 years ago gave scientists clues that the dinosaurs were indeed reptiles.  Once complete skulls were discovered in the subsequent decades — particularly the 1840s onward — it because quite clear that not only were they reptiles, but they were diapsids like most reptiles today, save for turtles and tortoises, which are anapsids.  The explanation to differentiate those anatomically cladistic terms is for a different article at a different time.

Given that the earliest evidence was that dinos were indeed reptiles, people therefore accepted it as a given that they were ectotherms.  After all, every species of reptile today is cold-blooded, why therefore not the dinosaurs from roughly 225 to 65 million years ago?  All that thinking changed with John Ostrom‘s discovery of Deinonychus in Montana in 1964.  All of a sudden, the bird-like characteristics of some of the feet and parts of the skeleton caused scientists to totally re-think dino metabolism, and eventually kicked off the great debate of warm-blooded — if not outright hot-blooded — vs. cold-blooded schools of thought.

The paper referenced in the linked article announcing its publication will, in all likelihood, not settle the debate, and for a valid reason.  It is easy to see the Carnosaurs, or meat-eaters, to be warm-blooded, as well as the less-vicious but very-much bipedal Coelurosaurs, what with their bird-like characteristics — albeit to varying extents — but what about the plant-eaters?  If, say, the Sauropods were warm-blooded, can one imagine how much energy it would require — in other words, how much plant matter they would have to eat — in order to sustain themselves?  It remains an intriguing question.

This time around, in the latest study, published in the scientific journal Nature, the scientists cite the bone growth rates of dinosaurs, and how they match up to all sorts of different species of modern mammals.  In the abstract, it affirms what has stood to reason within part of the paleontological community for roughly forty years.  What is left out in the piece, though, is what specific dino species’ bones were examined, and whether or not plant-eaters’ bones were part of this microscopic examination.  If they can demonstrate that, say, Sauropods had similar bone growth patterns as the established warm-blooded Theropods, then it shall open up the floodgates for all sorts of speculation about the sustenance behaviors of the vegetarian dinos, if nothing else!  Let the fascinating discoveries continue!