Research Training Program

Jorge Velez
University of Puerto Rico
Mayaguez, Puerto Rico

Matthew Carrano, Ph.D.
Supervising Scientist
Department of Paleobiology

“The fossils from Quarry Nine offer a unique window to the past; back to the real Jurassic Park”

Paleoecology of the Late Jurassic Morrison Formation based on microvertebrates from Quarry Nine

The paleoecology (ancient ecology) of the Late Jurassic (156 million years ago) Morrison Formation is poorly understood, even though the formation is one of the richest dinosaur-bearing rocks in the world. To be able to understand this ancient ecosystem it is important to develop a detailed study of the fossils found in the formation. For this study the fossils collected from a quarry of the Morrison formation called Quarry Nine were studied, highlighting the importance of the fossils of small vertebrates as a tool for reconstructing the paleoecology. The fossils collected from this quarry, yielded the single most important collection of small vertebrate from the Late Jurassic. Therefore, offering a unique insight into the Late Jurassic environment. Different types of mammals, turtles, fishes, dinosaurs, frogs, salamanders, lizards and crocodiles as well as freshwater snails and plants represent the paleoenvironment from Quarry Nine. New additions to the list of fossils vertebrates of Quarry Nine include one turtle, two fishes, one lizard, one frog, one pterosaur (flying reptiles) and eight dinosaurs. The occurrence of frogs and salamanders provide some evidence for freshwater lacustrine conditions. This is also supported by the abundance of turtle and crocodile remains and by the occurrence of freshwater plant fossils. The Quarry Nine represented lacustrine environment formed during seasonal wet and dry extremes, similar to the modern environment in the Gran Chaco plain of central South America.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates program, Award Number DBI-0243512.

Letter of gratitude