ERTH 2401 Lecture Notes - Lecture 9: Joseph Leidy, Ornithischia, Bighorn Sheep
Document Summary
Preservation overrepresentation of skulls suggests that only the most robust of bones, the skull caps, survived long journeys: due to its sturdiness over a dozen pachycephalosaurian species, north america (mainly montana and alberta, mainly skull caps, in river and lake sediments, skeletons are widely missing, transport in rivers along distances, asia, their remains are commonly found as nearly complete skulls, these fossils show little evidence of transport and were apparently fossilized close to where the living animal died, desert conditions, small streams, little evidence for transport. Distribution all in northern hemisphere: montana and alberta: mainly late cretaceous, most lived in asia (origin), apparently in a sahara like desert, migrated to europe and north america, the environments were very different, the rocks where marginocephalian remains are found represent broad, cretaceous coastal plain in a then temperate climate built from sediment eroded as the rockies mountain range rose to the west.
