|mhorn||Дата: Saturday, 02.07.2011, 23:09 | Сообщение # 1|
|Holwerda F.M. (2010) Middle-Jurassic basal sauropod teeth from Cerro Condor, Chubut, Patagonia, Argentina. A description and analysis of isolated basal sauropod teeth. M.Sc. thesis at the Biomarine Sciences Group, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands. |
A study has been done on Middle-Jurassic (Callovian) basal sauropod teeth from two localities in Chubut, Argentina: the Cerro Condor Sur site and the Las Chacritas site from Cerro Condor. The isolated teeth have been studied in terms of size, shape, and enamel wrinkling, and also in terms of microwear. The results reveal that teeth previously assigned to Patagosaurus fariasi (Bonaparte 1986) probably do not belong to that species. Two other teeth that have been assigned to Patagosaurus by (Rauhut 2003) are found to belong to Patagosaurus. Also, different teeth types are distinguished in terms of shape, size, denticles and enamel wrinkling between the two localities. Not all of these teeth can be assigned to currently known species of sauropod. This indicates that different species of sauropod dinosaurs inhabited the region. This conclusion is supported by postcranial skeleton material from the localities. The microwear analysis revealed different scratch directions for tooth MACN-CH 2008.3 between the mesial and distal side. The other teeth did not show significant outcomes in terms of microwear analysis, however the low variance between wearfacets may point to low niche differentiation for the sauropods in the Cerro Condor region.
Middle Jurassic - Lower Cretaceous ammonites & aptychi