I know that T. rex gets all the dinosaur press, but this one was too good not to mention. Researchers estimate that an adult Tyrannosaurus generated a bite force of between 35,000 and 57,000 newtons. For the record, that’s about four to six times more force than an alligator’s bite. It’s also more powerful than any other dinosaur’s measured bite, for that matter, including Allosaurus, Carnotaurus and, wow, even Giganotosaurus. Adult bite force was disproportionately greater than that of juveniles, which suggests a shift to different — and much larger — prey in adulthood. Via io9.

The Royal Ontario Museum has announced a new exhibition, Ultimate Dinosaurs: Giants from Gondwana, that I think I’m going to have to make time to see:

Surrounded by life-like environmental murals, the exhibition features real fossils, skeletons and 17 full-scale skeletal casts, many of which have never been seen before in Canada. ROM visitors will experience the world’s first display of Futalognkosaurus, a giant long-necked sauropod, one of the biggest animals to have ever walked the earth stretching 110 ft. long and weighing as much as 10 elephants. Also on display are Giganotosaurus, possibly the largest land predator to have ever lived, as well as the crocodile-faced spinosaur Suchomimus, and horned meat-eater Carnotaurus, and many more.

It’ll run from June 23, 2012 to January 6, 2013; I should be able to manage a visit to Toronto during that time. (Should I mention that the Canadian Museum of Nature has a Carnotaurus? They do.)

Brian Switek addresses a question that has preoccupied me for some time now: did tyrannosaurs have feathers, as some modern reconstructions have them? While no fossil tyrannosaur feathers have been found, tyrannosaurs were coelurosaurs, and nearly every kind of coelurosaur had feathered representatives. “What we can say is that the idea of a feather-covered Tyrannosaurus is a reasonable hypothesis.” But that covers a lot of possibilities, including partially feathered animals and feathered babies that lost their plumage as they grew up.

You think T. rex had wimpy little arms? Check out Carnotaurus, a South American theropod whose arms are even smaller, though those arms were robust and ended in four fingers. A new study examines the hand structure of Carnotaurus in the context of its abelisaurid relatives. Via Brian Switek.

Dave Hone interviews Adam Stuart Smith, a paleontologist who specializes in plesiosaurs and who’s also a keen illustrator of plesiosaurs, dinosaurs and other extinct beasties.

Previously: Paul Heaston’s Dinosaur Art; Nobu Tamora’s Dinosaur Drawings.

Here’s paleontologist Jack Horner giving a talk at TEDx Vancouver about dinosaur ontogeny — which is to say, the growth and development of dinosaurs. He begins by wondering where the little dinosaur fossils were, and ends by determining that radically different fossils are in fact the same species at different stages of growth: dinosaurs are more like birds than reptiles, and juveniles are not identical-but-smaller versions of the adult form. Horner’s not the best presenter, but it’s worth watching nonetheless. (This is something I’ve blogged about before: see Fewer Dinosaur Species and Metaplastic Bone and Triceratops, Torosaurus and Dinosaur Biodiversity.) Via Love in the Time of Chasmosaurs.

I love Paul Heaston’s pencil drawings of dinosaurs; he’s been colouring them digitally to great effect. Above, a Deinonychus in full plumage and (naturally) a sharply drawn T. rex. Via Love in the Time of Chasmosaurs.

Brian Switek again, arguing that using Tyrannosaurus as an all-encompassing point of reference for all paleontological news is starting to be a problem:

But our love for Tyrannosaurus can be unhealthy. You don’t need to look further than the headlines to see that the great Cretaceous predator has become the standard by which almost all of prehistory is judged. Dunkleosteus — a Devonian armoured fish — “had [a] bite stronger than a T. rex”; the invertebrate Hurdia was heralded as the “T. rex of the Cambrian period”; and, despite having a different shape, Colombia’s fossil snake Titanoboa was said to be “as big as T. rex”.

I’m almost convinced that there is a journalism guide that advises: “If a catchy headline doesn’t readily present itself for a new fossil discovery, a reference to T. rex will do at a pinch.”

T. rex: the Kevin Bacon of the prehistoric world.

Brian Switek’s Written in Stone: Evolution, the Fossil Record, and Our Place in Nature talks about the fossil record and Darwin’s theory of natural selection. That’s not as straightforward a subject as you might think: while the discovery of fossils of so-called transitional forms — Archeopteryx comes to mind — did much to fill in one readily admitted gap in Darwin’s theory, paleontologists weren’t always on-side with Darwin. Sure, they believed in evolution, but not necessarily that natural selection was the process; no few believed that evolution proceeded in a linear fashion, teleologically, from lesser to greater forms. Which is not what Darwinism is about. What the fossil record shows is not a linear progression, but a messy tree of life that is pruned as ecological niches disappear (at one point, for example, there were more than a dozen different kinds of horse in North America, with different kinds of horses adapted to different environments).

Switek builds his case chapter by chapter, looking at the fossil evolutionary record of everything from amphibians, mammals and birds to, more specifically, horses, whales, elephants and hominids. (It’s not, in other words, just a dinosaur book.) As a synthesis it’s an impressive virtuoso performance, wide-ranging without sacrificing depth. But I wonder whether it might not be too technical for beginners: I think I have enough amateur grounding in the language of taxonomy and cladistics not to have been bewildered by the book, but, you know, the clades do come fast and furious.

Switek has announced his next book, A Date with a Dinosaur, which will contrast dinosaurs in the popular imagination with the latest research. His article in today’s Wall Street Journal gives some indication of how he’ll deal with that subject.

I do love dinosaur exhibits. This Saturday, a new one opens at the American Museum of Natural History in New York; it’s called The World’s Largest Dinosaurs, and it features a 60-foot model of a Mamenchisaurus. That’s right: it’s all about the sauropods, baby! Gothamist and UPI both have sneak-preview photo galleries.

Zhuchengtyrannus magnus, a newly discovered species of tyrannosaur, was announced this week: a big bloke in the same size class as Tyrannosaurus or Tarbosaurus, described from tooth and jaw fragments found in Shandong province, China. The article is in press at Cretaceous Research; the lead author, Dave Hone, talks about it on his blog. More at Dinosaur Tracking and from BBC News.

In a previous entry I made reference to something called a thagomizer. This is what the spikey bit at the end of a stegosaur’s tail is called. The name comes from a Far Side cartoon (in which a caveman lecturer points to a stegosaur’s tail and calls it the thagomizer, “after the late Thag Simmons”) in 1982. In the 1990s, paleontologists began using it informally to describe collectively the spikes at the end of a stegosaur’s tail, because it was fun, and they had no other term for it. It caught on. (I, for one, will never get tired of using the word.)

Today, Brian Switek writes about what the fossil record says about the use of the thagomizer as a weapon — for example, the existence of a thagomizer-shaped hole in an Allosaurus bone.

Here’s a short video from the American Museum of Natural History, showing the work of the fossil preparator — the technician who prepares a fossil by, among other things, removing the rock surrounding the fossilized bone (the “matrix”). Via Brian Switek.

Brian Switek places that recent study suggesting that there were too many Tyrannosaurus in the fossil record for it to have been an apex predator in the context of an 18-year debate about Tyrannosaurus’ scavenging ways. “That Tyrannosaurus was an opportunistic carnivore that both hunted and scavenged isn’t news. Paleontologists have been saying this in response to Horner’s ‘obligate scavenging’ hypothesis for years, and Holtz specifically drew comparisons to predators like spotted hyenas. [Which primarily hunt, but also scavenge. —JC] What is noteworthy is that Horner appears to have softened his original hypothesis to the point where I was surprised that Holtz’s paper was not cited as a more direct source of support for Tyrannosaurus as an opportunistic feeder.”

Previously: Too Many Tyrannosauruses.

The predator-vs.-scavenger debate regarding Tyrannosaurus rex has been going on forever. Via io9 comes word of a new study that adds fuel to the “scavenger” side of the argument. Co-authored by well-known paleontologist Jack Horner, long in the T. rex-as-scavenger camp, the study points out that are too many T. rex fossils in the Hell Creek bone bed relative to herbivore fossils for it to have been an apex predator. (There can only be so many predators for a given population of herbivores, or else there’s not enough food.) Which suggests that T. rex had other food sources to keep it going — like scavenging. Which is not to say that T. rex wasn’t a bad mofo, or that it couldn’t hunt, only that — assuming that the dinosaur census is a representative sample — hunting wouldn’t have been enough to feed that ravenous maw of nom.

On Love in the Time of Chasmosaurs, a blog about dinosaurs and pop culture, David Orr has an interview with dinosaur illustrator Nobu Tamura, who has uploaded hundreds of drawings of prehistoric species to the Wikimedia Commons and made them freely available under a Creative Commons licence — I’ve used them several times myself to illustrate my own dinosaur blog entries. (Above: Tamura’s drawing of Utahraptor ostrommaysorum).

Dinosaur blogger Brian Switek has a piece on Smithsonian.com about dinosaur sex, an expansive subject hampered by the lack of preserved soft tissue. It turns out that female dinosaurs can be identified by the presence of medullary bone, from which age at reproduction can be determined; and there are plenty of fossilized battle scars, evidence of mating combat. But we still don’t know the answer to this vital question: how the heck did Stegosaurus, with all those bony plates and that thagomizer, mate?

Figuring out how Stegosaurus even could have mated is a prickly subject. Females were just as well-armored as males, and it is unlikely that males mounted the females from the back. A different technique was necessary. Perhaps they angled so that they faced belly to belly, some have guessed, or maybe, as suggested by Timothy Isles in a recent paper, males faced away from standing females and backed up (a rather tricky maneuver!). The simplest technique yet proposed is that the female lay down on her side and the male approached standing up, thereby avoiding all those plates and spikes. However the Stegosaurus pair accomplished the feat, though, it was most likely brief — only as long as was needed for the exchange of genetic material. All that energy and effort, from growing ornaments to impressing a prospective mate, just for a few fleeting moments to continue the life of the species.

(Illustration by Nobu Tomura. Creative Commons licence.)