Thursday, August 07, 2008

Amphibians and reptiles from the Gran Dolina cave and the evolution of landscape in Atapuerca

This study deals with the amphibians (newts, toads and frogs) and squamate reptiles (amphisbaenian, lizards and snakes) bone remains proceeding from the 1993-1999 washing-sieving campaigns in the river Arlanzon in Atapuerca. Nearly 5.5 tones of sediment have been processed from the excavation-test of Gran Dolina (levels TD5 to TD10), an excavation realized in order to evaluate the potential of the locality and that furnished the first remains of Homo antecessor in the TD6 level. The material corresponds approximately to 40.000 fossils attributed to 22 taxons (genus and species).

Some drawings of amphibian fossil remains from Gran Dolina, Atapuerca, made by H.-A. Blain. It is a matter of midwife toad, western spadefoot, natterjack toad, european toad and common frog.

This work (based o part of the Ph.D. thesis of the first author) constitutes the first intent to reconstruct past landscape of the Sierra de Atapuerca during the early to middle Pleistocenes using amphibian and aquamate reptile assemblages.

The reconstructed landscape along the sequence of Gran Dolina has been compare with the data from other palaeoenvironmental proxies as small-mammals (rodents, shrews, bats, and rabbits), palynology (pollen and spores) and geomorphology

Meticulous sieving-washing of the excavated sediment in order that no fossil goes unnoticed, small though it was - Jordi Mestre / IPHES

The analyze of the evolution of the biodiversity (taxonomical associations) of reptiles and amphibians during approximately 600.000 years (from 900.000 to 300.000 years) in Gran Dolina has permitted to show that permanent aquatic and humid habitats ever been present in the vicinity of the site. However during the warmest periods, more open and dryer biotopes are best represented, whereas during cold periods humid meadows and woodland are predominant.

From: Blain H.-A., Bailon, S. & Cuenca-Bescós, G. (2008): The Early-Middle Pleistocene palaeoenvironmental change based on the squamate reptile and amphibian proxy at the Gran Dolina site, Atapuerca, Spain. Palaeogeography, Palaeoclimatology, Palaeoecology, 261 (1-2): 177-192.