Odontological and osteological investigations on propalaeotheriids (Mammalia, Equidae) from the Eocene Geiseltal Fossillagerstätte (Central Germany) - a full range of extraordinary phenomena
Hellmund, Meinolf
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 267 Heft 2 (2013), p. 127 - 154
veröffentlicht: Feb 1, 2013
DOI: 10.1127/0077-7749/2013/0300
ArtNo. ESP155026702001, Preis: 29.00 €
Abstract
The high amount of dentitions of propalaeotheres from the Geiseltal Fossillagerstiitte, especially from the vertebrate site “XIV in the “Unterkohle (MP 11), allows a detailed insight into the various phenomena how teeth may develop and display within their life time. These are wear, loss or tooth replacement, irregular insertions, supernumerary teeth and even mechanical post-mortem wear through mechanical polishing. Pathological structures in bones also rarely occur. The succession of replacing the milk dentition step by step and the eruption of the permanent teeth are demonstrated in the fossil record within a lot of different individual ages. It is striking that nothing is happening occasionally here, but in a definite order. Therefore we can distinguish and establish a descriptive “classification in the sense of “... older or younger as ... or “juvenile, subadult (“transitional), adult and senile. This descriptive method makes sense in palaeontology, however, annualising the classification is impossible. In order to document irregularities in dentitions as discussed here, it is highly necessary and even indispensable, to excavate a “quantum satis of specimens for comparison from one and the same locality. The vertebrate site “XIV contributed numerous equid fossils over a time span of at least four years of excavation. Due to that, a highly interesting result is verified for the maxillaries and mandibles of propalaeotheriids of the Geiseltal Fossillagerstiitte. As in other rapidly growing mammals, all three molars of the propalaeotheres usually erupt before their deciduous teeth were replaced, a procedure which is called “Schultz's rule.
Schlagworte
eocene • geiseltal fossillagerstiitte • propalaeotherium • eurohippus • dentition • wear • tooth anomalies • “schultz's rule“