Christopher Noto

Publications (4) View all

• Source

  Available from: Christopher Noto

  Article: FEEDING TRACES AND PALEOBIOLOGY OF A CRETACEOUS (CENOMANIAN) CROCODYLIFORM: EXAMPLE FROM THE WOODBINE FORMATION OF TEXAS

  CHRISTOPHER R. NOTO, DEREK J. MAIN, STEPHANIE K. DRUMHELLER
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  ABSTRACT: Direct evidence of behavior in extinct tetrapods is rare. However, these traces can inform a variety of research questions touching on paleoecology, taphonomy, and functional morphology. Here we present fossil specimens from the Upper Cretaceous (Cenomanian) Woodbine Formation that exhibit tooth marks consistent with predation by a new taxon of large crocodyliform currently under study. Collected from the recently discovered Arlington Archosaur Site, the marked bones were largely found in a single peat horizon and in close association with the new crocodyliform. The feeding traces themselves consist of pits, scores, and punctures that occur on multiple turtle shell fragments and two dinosaur limb bones. The pattern of marks and the breakage on turtle carapaces and plastra suggest that they were crushed, whereas the marks on dinosaur bones indicate possible dismemberment. These interpretations and the association with a crocodyliform trace maker are based on observations of feeding behaviors and accompanying, diagnostic bite mark patterns made by extant crocodylians. The morphology of the new crocodyliform taxon and the distribution of bite marks indicates it was likely a generalist: an opportunistic predator that fed on a variety of prey, including turtles and dinosaurs. Given this evidence and the paleoenvironmental setting, the ecology of the large crocodyliform from the Woodbine Formation was likely most similar to that of fossil and living crocodylians inhabiting delta-plain environments. Not only were these crocodyliforms likely significant predators in the Woodbine paleoecosystem, they also played an important taphonomic role in the assembly of vertebrate remains from the surrounding community.
  Palaios 03/2012; · 1.80 Impact Factor
• Chapter: Hierarchical Control of Terrestrial Vertebrate Taphonomy Over Space and Time: Discussion of Mechanisms and Implications for Vertebrate Paleobiology

  Christopher R. Noto
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  ABSTRACT: There is no doubt among paleontologists that the fossil record of terrestrial vertebrates is fragmented and unevenly distributed over space and time. The underlying causes of this patchiness derive from a combination of factors occurring before and after the deposition of vertebrate remains. Large-scale vertebrate fossil distribution patterns present challenges in addressing the effects of small-scale taphonomic processes on distribution patterns, and what, if any, effect they may have on biodiversity reconstructions. This chapter presents a hierarchical model connecting small-scale taphonomic processes and large-scale fossil preservation patterns. Factors acting at higher levels in the hierarchy constrain the range of taphonomic processes acting at lower levels, whereas lower level processes are responsible for determining vertebrate preservation and the resulting fossil record for an area. Secular changes in climate, tectonics, sea-level, etc. alter the distribution of both environments and biodiversity over time. These changes in turn may alter the congruence between standing biodiversity and the fraction of that diversity faithfully represented in the fossil record, skewing our understanding of extinct vertebrate ecosystems and their evolution over time.
  11/2010: pages 287-336;
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  Available from: Christopher Noto

  Article: Broad-scale patterns of late jurassic dinosaur paleoecology.

  Christopher R Noto, Ari Grossman
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  ABSTRACT: There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs. Fewer studies have sought to determine if the ecological structure of fossil assemblages is preserved and, if so, how dinosaur communities varied. Climate is a major component driving differences between communities. If the ecological structure of a fossil locality is preserved, we expect that dinosaur assemblages from similar environments will share a similar ecological structure. This study applies Ecological Structure Analysis (ESA) to a dataset of 100+ dinosaur taxa arranged into twelve composite fossil assemblages from around the world. Each assemblage was assigned a climate zone (biome) based on its location. Dinosaur taxa were placed into ecomorphological categories. The proportion of each category creates an ecological profile for the assemblage, which were compared using cluster and principal components analyses. Assemblages grouped according to biome, with most coming from arid or semi-arid/seasonal climates. Differences between assemblages are tied to the proportion of large high-browsing vs. small ground-foraging herbivores, which separates arid from semi-arid and moister environments, respectively. However, the effects of historical, taphonomic, and other environmental factors are still evident. This study is the first to show that the general ecological structure of Late Jurassic dinosaur assemblages is preserved at large scales and can be assessed quantitatively. Despite a broad similarity of climatic conditions, a degree of ecological variation is observed between assemblages, from arid to moist. Taxonomic differences between Asia and the other regions demonstrate at least one case of ecosystem convergence. The proportion of different ecomorphs, which reflects the prevailing climatic and environmental conditions present during fossil deposition, may therefore be used to differentiate Late Jurassic dinosaur fossil assemblages. This method is broadly applicable to different taxa and times, allowing one to address questions of evolutionary, biogeographic, and climatic importance.
  PLoS ONE 01/2010; 5(9):e12553. · 4.09 Impact Factor
• Chapter: Dinosaur Distribution

  D. B. Weishampel, J. Le Loeuff, R. A. Coria, E. M. P. Gomani, X. Zhao, X. Xu, P. M. Barrett, A. Sahni, C.R. Noto
  01/2004: pages 517-606;