Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs

  title={Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs},
  author={Gregory M. Erickson and Peter J Makovicky and Philip J. Currie and Mark A. Norell and Scott A. Yerby and Christopher A. Brochu},
How evolutionary changes in body size are brought about by variance in developmental timing and/or growth rates (also known as heterochrony) is a topic of considerable interest in evolutionary biology. [] Key Result T. rex had a maximal growth rate of 2.1 kg d-1, reached skeletal maturity in two decades and lived for up to 28 years. T. rex's great stature was primarily attained by accelerating growth rates beyond that of its closest relatives.
Sexual maturity in growing dinosaurs does not fit reptilian growth models
It is shown by counting lines of arrested growth and performing growth curve reconstructions that Tenontosaurus, Allosaurus, and Tyrannosaurus were reproductively mature by 8, 10, and 18 years, respectively, which suggests that these dinosaurs were born relatively precocial and experienced high adult mortality.
Osteohistological analyses reveal diverse strategies of theropod dinosaur body-size evolution
The first evidence of a lack of strong mechanistic or physiological constraints on size evolution in the largest bipeds in the fossil record is provided and evidence of one of the longest-living individual dinosaurs ever documented is provided.
Dinosaur paleohistology: review, trends and new avenues of investigation
It is suggested that the combination of histological and molecular methods holds great potential for examining the preserved tissues of dinosaurs, basal birds, and their extant relatives, and the development of novel techniques with which to further investigate important paleontological questions are discussed.
Developmental patterns and variation among early theropods
  • C. T. Griffin
  • Geography, Environmental Science
    Journal of anatomy
  • 2018
This work used ontogenetic sequence analysis (OSA) to reconstruct developmental sequences of morphological changes in the postcranial ontogeny of the early theropods Coelophysis bauri and Megapnosaurus rhodesiensis, both of which are known from large sample sizes.
Assessing dinosaur growth patterns: a microscopic revolution.
  • G. Erickson
  • Geography, Environmental Science
    Trends in ecology & evolution
  • 2005
Longevity and growth rate estimates for a polar dinosaur: a Pachyrhinosaurus (Dinosauria: Neoceratopsia) specimen from the North Slope of Alaska showing a complete developmental record
Our knowledge of growth dynamics in large ceratopsian dinosaurs is very poor, in part, due to the paucity of quantifiable age markers such as growth lines in their bones. We sought marker-based,
Relative growth rates of predator and prey dinosaurs reflect effects of predation
Comparisons with several small and large predatory theropods reveal that MOR 549 grew faster and matured sooner than they did, suggesting that Hypacrosaurus was able to partly avoid predators by outgrowing them.
Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy “Nanotyrannus” and supports ontogenetic niche partitioning in juvenile Tyrannosaurus
Together, the results support the synonomization of “Nanotyrannus” into Tyrannosaurus and fail to support the hypothesized presence of a sympatric tyrannosaurid species of markedly smaller adult body size, but suggest that this species singularly exploited mid- to large-sized theropod niches at the end of the Cretaceous.
The evolution of intraspecific variation, growth, and body size in early theropod dinosaurs
The authors' analyses suggest intraspecific variation in growth is high in early dinosaurs but largely absent in birds, and non-metric multidimensional scaling analysis suggests this variation is not related to sexual differences.
Rise of dinosaurs reveals major body-size transitions are driven by passive processes of trait evolution
A new body-size dataset of more than 400 therapsid and archosauromorph species spanning the Late Permian–Middle Jurassic is analysed, indicating intrinsic, biological factors are more important than the external environment and maximum size of Middle–early Late Triassic archosuromorph predators exceeds that of contemporary herbivores.


Dinosaurian growth patterns and rapid avian growth rates
It is shown that dinosaurs exhibited sigmoidal growth curves similar to those of other vertebrates, but had unique growth rates with respect to body mass.
On the Evolution and Adaptive Significance of Postnatal Growth Rates in the Terrestrial Vertebrates
  • T. Case
  • Biology, Environmental Science
    The Quarterly Review of Biology
  • 1978
The results of this analysis support the notion that growth rate is adapted to certain features of an animal's environment, which will be altered in an empirically appropriate direction with changes in these environmental parameters.
Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria)
An increase in tooth width, accompanied by loss of tooth positions, and a global shift from an immature gracile to a mature robust morphotype in the craniofacial skeleton typifies the ontogenetic changes in T. rex.
Skull structure and evolution in tyrannosaurid dinosaurs
The analysis of cranial characters and comparison of postcranial features reveal that Tarbosaurus bataar is not the sister taxon of Tyrannosaurus rex, and should be considered a genus distinct from Tyrannosaurus.
A new giant carnivorous dinosaur from the Cretaceous of Patagonia
A new giant carnivorous dinosaur from the Upper Creta-ceous of northwestern Patagonia (Argentina) is reported, characterized by a proportionally low skull, a reduced shoulder girdle, and robust vertebrae and hind limbs, and provides an opportunity to exam-ine the Gondwanan dinosaur palaeocommunities and their relation to those from Laurasia.
Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada
  • P. Currie
  • Environmental Science, Geography
  • 2003
It is concluded that the most parsimonious interpretation of relationships leads to the separation of the two species of Albertosaurus into Gorgosaurus libratus from the Campanian Dinosaur Park Formation and Albertosaurus sarcophagus from the upper Campanian/lower Maastrichtian Horseshoe Canyon Formation.
  • P. Currie
  • Environmental Science, Geography
  • 1998
In 1910, a collecting party from the American Museum of Natural History led by Barnum Brown floated down the Red Deer Riverof Alberta. In the Horseshoe Canyon Forma­ tion (Edmonton Group,
Body mass increased allometrically with total length in all groups of dinosaurs, but 95% confidence intervals were very large for Ankylosauria and Stegosauria so that the resulting regression equations have little predicting power.
Pelvic and hindlimb musculature of Tyrannosaurus rex (Dinosauria: Theropoda)
A new reconstruction of the pelvic and hindlimb muscles of the large theropod dinosaur Tyrannosaurus rex is developed, using data from both extant and fossil turtles, lepidosaurs, and archosaurs to constrain inferences concerning the soft‐tissue structures in T. rex.
Physiological implications of the bone histology of Syntarsus rhodesiensis (Saurischia: Theropoda)
The general bone histology is described initially and thereafter follow speculations on the animal's thermoregulatory ability, possible evidence for sexual dimorphism, and also the probable growth strategy it employed, as reflected in its bone Histology.