Publication Year: 2013
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. This volume, drawn from the symposium, includes studies of the tyrannosaurids Chingkankousaurus fragilis and "Sir William" and the generic status of Nanotyrannus; 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. Tyrannosaurid Paleobiology highlights the far ranging and vital state of current tyrannosaurid dinosaur research and discovery.
Published by: Indiana University Press
Series: Life of the Past
Tyrannosaurus rex is assuredly the dinosaur with the greatest public visibility, and it has been cast as a heavy in countless films dating back to Harry Hoyt’s (1925) adaptation of Sir Arthur Conan Doyle’s (1912) Lost World. However, as of 1980, only seven specimens of the dinosaur were known (Larson 2008). In the last three decades, this number has swelled ...
Part 1 Systematics and Descriptions
1 Phylogenetic Revision of Chingkankousaurus fragilis, a Forgotten Tyrannosauroid from the Late Cretaceous of China
Recent discoveries, especially the feathered theropods of the Jehol Biota, have placed China at the forefront of contemporary dinosaur research (e.g., Chen et al. 1998; Xu et al. 2003; Norell and Xu 2005; Xu and Norell 2006). However, vertebrate paleontology has a long history in China, and the country’s rich dinosaur fossil record has been explored for over a century. ....
2 The Case for Nanotyrannus
The genus Nanotyrannus was erected in 1988 by Bakker, Williams, and Currie, redescribing a skull (CMNH 7541) from the Maastrichtian (Lan-cian) Hell Creek Formation of Montana, first described as Gorgosaurus lancensis by Gilmore (1946). In part due to the absence of additional specimens, the validity of Nanotyrannus came under question by ...
3 Preliminary Analysis of a Sub-adult Tyrannosaurid Skeleton from the Judith River Formation of Petroleum County, Montana
In 2002 we discovered an enigmatic theropod skeleton approximately 15 miles northwest of the town of Melstone, Montana, along the Petroleum/ Musselshell county line. Based upon the size, robustness, and interpreted stratigraphic position (the lower third of the Hell Creek Formation) of the exposed elements, the skeleton, at the time, was thought to be a sub-adult Tyrannosaurus rex. Recent, detailed geologic mapping in the ...
Part 2 Functional Morphology and Reconstruction
4 Internal Structure of Tooth Serrations
Serrations on the teeth of vertebrates are functional, but they have only a few characteristic external shapes that are only a partial aid to identifi - cation. Internal structure of serrations can be both functional and characteristic. Thus, serrations easily differentiated on the basis of internal structure include those of a phytosaur (with internal peak), Dimetrodon ...
5 Feet of the Fierce (and Not So Fierce): Pedal Proportions in Large Theropods, Other Non-avian Dinosaurs, and Large Ground Birds
The extent to which the makers of tridactyl dinosaur footprints can be identifi ed depends on the extent to which their foot skeletons can be told apart. We examined this question for non-avian theropod dinosaurs (NATs) and large ground birds, making additional comparisons with functionally tridactyl, bipedal – or potentially bipedal – ornithischians. ...
6 Relative Size of Brain and Cerebrum in Tyrannosaurid Dinosaurs: An Analysis Using Brain-Endocast Quantitative Relationships in Extant Alligators
Brain and cerebrum mass are estimated from endocasts of three tyrannosaurid taxa (Tyrannosaurus rex, Gorgosaurus, and Nanotyrannus) using morphological and quantitative brain-endocast relations in a size series of sexually mature alligators (Alligator mississippiensis). The alligator size series (N = 12) ranged from the smallest sexually mature size to the largest size commonly encountered. ...
7 Jane, in the Flesh: The State of Life-Reconstruction in Paleoart
My goal in creating a fl esh reconstruction of an extinct animal is to provide the museum visitor with a sense of what the real live animal was all about. I don’t want to give the exhibit viewer a cliché, a toy, a Hollywood prop, or something that’s been seen in every kid’s dinosaur book. I want the observer to see a restoration that is unique, that shows a creature, frozen in time, that endured ...
8 A Comparative Analysis of Reconstructed Jaw Musculature and Mechanics of Some Large Theropods
Tyrannosaurus rex was compared, in terms of estimated lever arm and extension of the jaw adductors, with Daspletosaurus torosus, Nanotyrannus lancensis, Allosaurus fragilis, and Ceratosaurus nasicornis. Daspletosaurus torosus agrees reasonably closely with T. rex in these parameters, indicating that no great differences in feeding adaptation were apparent from this data. Nanotyrannus differs more from T. rex; these differences appear to be related to the relatively lower skull of N. lancensis and suggest ...
9 Tyrannosaurid Craniocervical Mobility: A Preliminary Qualitative Assessment
Tyrannosaurs were dynamic predators, and the analysis of craniocervical mobility has implications for the biomechanics of their foraging and feeding. The cervical vertebrae of tyrannosaurids are anteroposteriorly shorter than those of many other coelurosaurs, as well as some extant birds, and the neck is correspondingly less fl exible. Variation of vertebral ...
Part 3 Paleopathology, Paleoecology, and Taphonomy
10 Clawing Their Way to the Top: Tyrannosaurid Pathology and Lifestyle
Facial scars in tyrannosaurids have been attributed to intraspecifi c biting behavior. Remodeled bone surrounding the lesions document survival of these attacks/interactions. While that is a reasonable hypothesis, examination of recently discovered specimens suggests an alternative explanation. The “Jane” and “Peck” Tyrannosaurus rex specimens have substantial ...
11 Brodie Abscess Involving a Tyrannosaur Phalanx: Imaging and Implications
Osteomyelitis is rarely found in dinosaur fossils. When it is identifi ed, the bone lesion shows characteristic, chronic changes of disorganized osseous overgrowth resulting in distortion of the bone. We present a focal bone lesion compatible with osteomyelitis involving a tyrannosaur phalanx. Computed tomographic (CT) imaging disclosed typical fi ndings of a type ...
12 Using Pollen, Leaves, and Paleomagnetism to Date a Juvenile Tyrannosaurid in Upper Cretaceous Rock
The juvenile tryrannosaurid from the Hell Creek Formation (Upper Cretaceous: Maastrichtian) in southeastern Montana, informally named “Jane” (BMR P2002.4.1), is determined to be from a zone in the formation that dates to about 66 Ma. The stratigraphic position of the Jane site is established on the basis of palynology and paleobotany by comparison with correlative sections in southwestern North Dakota and is supported ...
13 The Biomechanics of a Plausible Hunting Strategy for Tyrannosaurus rex
We present here a biomechanical analysis of a hunting strategy that Tyrannosaurus rex could have employed effectively. The modern analogy for this hunting strategy is “cow tipping,” in which reckless people ambush and tip cows over. Although this analogy seems odd, it is apt. Anatomical analysis of Triceratops indicates that, like a cow, if it were ...
14 A Closer Look at the Hypothesis of Scavenging versus Predation by Tyrannosaurus rex
Controversy surrounds the feeding behavior of the large theropod Tyrannosaurus: Was it an obligate scavenger, a predator, or an opportunist that scavenged as well as hunted? Evidence for an obligate scavenging lifestyle is examined: Enlarged olfactory lobes, allegedly for carrion detection, are shown to also occur in extant non-scavenging predators and in other dinosaurs. Eyesight may have been poor in low light but otherwise acute. ...
15 New Evidence for Predation by a Large Tyrannosaurid
A partial skeleton of a hadrosaur believed to be Brachylophosaurus canadensis shows evidence of a failed attack by a large theropod, possibly Daspletosaurus sp. The injury consists of damage to the neural spines of the last sacral vertebra and fi rst two caudal vertebrae. Remodeled bone, even at the site of the traumatic ...