The reason why this happens is because the skull is made of bone, and bone is a living tissue that responds to local mechanical stimuli, such as the brain pushing up into it. They had skulls 6 feet long, stood 22 feet high at the shoulder, and were twice as heavy as the largest elephant ever recorded, tipping the scales at 44,100 pounds. The opening of an exhibit focused on “Jane,” a beautifully preserved tyrannosaur collected by the Burpee Museum of Natural History, was the occasion for an international symposium on tyrannosaur paleobiology. A Pedunculate Cirripede from the Upper Silurian of Oesel, Esthonia. I had the chance to skim the relatively new Tyrannosaurid Paleobiology, a research compendium edited by Parrish, Molnar, Currie & Koppelhus, and published by Indiana University Press. Pterosaurs achieved flight with a flexible and elastic membrane, the cheiropatagium (ch), stretching between the arm and legs, supported only by a single elongated fourth digit, the so-called wing finger (wf). The skull is too thick for these effects to be seen on its outside, but they are clear enough on the inside that they are even fossilised. [PDF] and the Evolution of Bird Flight [.zip] Alexander DE, Gong E, Martin LD, Burnham DA & Falk AR. Model tests of gliding with different hindwing configurations in the four-winged dromaeosaurid Microraptor gui. This volume, drawn from the symposium, includes studies of the tyrannosaurids ; theropod teeth, pedal proportions, brain size, and craniocervical function; soft tissue reconstruction, including that of “Jane”; paleopathology and tyrannosaurid claws; dating the “Jane” site; and tyrannosaur feeding and hunting strategies. Untersuchungen zur Morphologie, Taxonomie und Phylogenie der Chelicerata II. Journal of Zoological Systematics and Evolutionary Research 17, 177-200. Impressive book that goes through the variety of research programmes now happening on the biology of tyrannosaurs, highly-recommended if you can chew through the technical nature of the book. The membrane was also reinforced by fibers inside it (Kellner et al., 2010). They also had a cheripatagium (cr), a small mebrane in the elg, and a propatagium (pro) in front of the arm, supported by the pteroid bone (pt), the functional morphology of which has been the subject of debate for decades. However, the brain can influence the inside of a skull. The episode known as the Great American Biotic Interchange, perhaps the most important of all natural history “experiments,” is also an important theme of the book, tracing the biotic events of both North and South America that led to the fauna and the ecosystems discussed in this book.. Birds have feathers stuck in the skin of the arm and hand, and they act as the flight surface. You all know what the outside of a human brain looks like: it’s a dense maze of grey matter grooves and ridges (sulci and gyri, respectively). If you look at the inside of a human braincase, you will see that the cerebral cortex’s torturous pattern is etched onto it. Distorted Microraptor specimen is not ideal for understanding the origin of avian flight. These massive animals inhabited Asia and Eurasia for more than 14 million years, about 37 to 23 million years ago. Prothero tells their story, from their discovery just a century ago to the latest research on how they lived and died. The bat forelimbs have four elongated digits acting as supports for a membrane that acts as an aerofoil. Discovery of a rare arboreal forest-dwelling flying reptile (Pterosauria, Pterodactyloidea) from China.
Most importantly, the brain does not work that way – rarely are personality traits mappable to individual sections. Assessing Arboreal Adaptations of Bird Antecedents: Testing the Ecological Setting of the Origin of the Avian Flight Stroke. Megafauna describes the history and way of life of these animals, their comings and goings, and what befell them at the beginning of the modern era and the arrival of humans. Cranial mechanics and feeding in Tyrannosaurus rex. Cosimo Alessandro Collini was the first to describe a pterosaur back in 1784, based on specimens from the Late Jurassic of Germany. In 1801, legendary palaeontologist Georges Cuvier took a look at it and reinterpreted it as a flying reptile, later naming Pterodactylus and setting the stage for the modern study of pterosaurs.
Vertebrate palaeontologists can take a fossil skull and fill it with latex rubber to make a mould. The following books released this year cover palaeontology and palaeobiology. Untersuchungen zur Morphologie, Taxonomie und Phylogenie der Chelicerata I. Journal of Zoological Systematics and Evolutionary Research 17, 85-116. This post is just a collection of small facts about tyrannosaurs. Tyrannosaurus rex is probably the most famous dinosaur, thanks to its general fearsome appearance (lessened nowadays by the knowledge it had feathers) and its misplaced casting in Jurassic Park, even though its a Late Cretaceous dinosaur. rex is a 12 meter long, 5 ton tyrannosauroid (Brochu, 2003), a group of large, basal coelurosaur theropod dinosaurs (Holtz, 1994) that originated in the Middle Jurassic as part of the general dinosaur radiation of the time (Xu et al., 2006). rex is the most famous, tyrannosaurs were actually fairly diverse (other famous names include Albertosaurus, Daspletosaurus, Tarbosaurus), even including a possible dwarf species, Nanotyrannus lancensis, that could just be a juvenile T. Research into tyrannosaurs is now booming thanks to a spate of new species discoveries over the past decade (Brusatte et al., 2010b). Similar to birds, pterosaurs had a highly-efficient air sac system for respiration, saving a lot of weight by hollowing out the bones (Claessens et al., 2009). Evolution of morphological disparity in pterosaurs.
So, according to the chart above, the skull around my ear would be a great cavity because I’m not active, destructive, or very hungry. Without this cell there would be nothing on Earth today except bacteria, and the formation of this cell was a fundamental turning point in the history of life on Earth. Xu X, Clark JM, Forster CA, Norell MA, Rickson GM, Eberth DA, Jia C & Zhao Q. A basal tyrannosauroid dinosaur from the Late Jurassic of China. There is a brand new book on pterosaurs out: Witton’s Pterosaurs: Natural History, Evolution, Anatomy, published by Princeton University Press.
But I would have bumps around my eye because of my serial multilinguality and my obsession with order. The evolutionary continuum of limb function from early theropods to birds. More than 10,000 years ago spectacularly large mammals roamed the pampas and jungles of South America. Vertebrate palaeontologist friends are telling me it’s a stunning and masterful book, suitable both for the lay public and as a reference work, so if you have any interest at all in pterosaurs, get it. An unusual long-tailed pterosaur with elongated neck from western Liaoning of China. High lift function of the pteroid bone and forewing of pterosaurs.
The diagram above is a phrenological one, and the phrenologist would feel up and measure the bumps on a person’s skulls. She shares the difficulties and pleasures encountered in finding rare fossils and describes the changing views on early mammals made possible by these discoveries. The logic was simple: if a person has a bump, then the brain region beneath the skull must be larger, and therefore whatever that region represented would be highly-manifested in that person. Using Physical Models to Study the Gliding Performance of Extinct Animals. Covering the period from 1 to 2 billion years ago – a period [Brasier] once dubbed ‘the boring billion’ – he demonstrates how it in fact involved great evolutionary potential with the formation of the complex (eukaryotic) cell.