Story of 4.5-Million-Year-Old Whale Found in Spain
In 2006, a team of Spanish and American researchers found the fossil remains of a whale, 4.5 million years old, in Bonares, Huelva. Now they have published, for the first time, the results of the decay and fossilisation process that started with the death of the young cetacean, possibly a baleen whale from the Mysticeti group.This is not the first discovery of the partial fossil remains of a whale from the Lower Pliocene (five million years ago) in the Huelva Sands sedimentary formation, but it is the first time that the results of the processes of fossilisation and fossil deposition following the death of a whale have been published.The work of this international group, published in the latest issue of Geologica Acta, is the first taphonomic (fossilisation process) study done on cetacean remains combined with other paleontological disciplines such as ichnology (the study of trace fossils)."Once the whale was dead, its body was at the mercy of scavengers such as sharks, and we know that one of these voracious attacks resulted in one of its fins being pulled off and moved about ten metres. It remained in this position in the deposit studied," Fernando Muñiz, one of the study’s authors and a researcher in the University of Huelva’s "Tectonics and Paleontology" research group, currently working as a palaeontologist for the City Council of Lepe, in Huelva, said.The researchers have described the fossil remains discovered in Bonares, Huelva, at an altitude of 80 metres above sea level and 24 kilometres from the sea, and have studied the main taxonomic characteristics and associated fauna. The team also created a paleoenvironmental model to explain how the skeleton -- which is incomplete apart from some pieces such as its three-metre-long hemimandibular jaw bones -- was deposited.The results show that these remains came from a "juvenile whale that died and became buried on the sea floor, at a depth of around 30-50 metres, and were subject to intense activity by invertebrate and vertebrate scavengers (as can be seen from the presence of numerous shark teeth associated with the bones)," says Muñiz. Based on the remains studied, it is hard for the researchers to say whether the cause of death was illness, old age, or attack by a larger predator.In terms of its taxonomic description, the researchers say this is "difficult," although the morphology of the scapula (shoulder blade) suggests it is "from the Balaenopteridae (rorqual) family, belonging to the group of baleen whales from the Mysticeti sub-order," says the paleontologist.