I saw this in the news last week on the BBC and Guardian website. These stories explained that as a result of mass strandings 5 million years ago over 40 marine mammals have been discovered. This all came about when the Pan-American highway was being widen and bones could be seen sticking out of rock faces. researchers, from both the US and Chile, were given two weeks to excavate the site before work continued on the road. In order to obtain as much information from the bones as possible they were recorded using 3D digitalising tools whilst they remained in situ and were then removed for further research in the lab.
In addition to the news articles I went in search for the published paper of the site (see full citation below). This gave a much more detailed account of the findings, including a list of the species identified and the location of each individual. Multiple species of marine mammals were excavated including large whales, seals and an extinct type of sperm whales. These mammals ranged from calves to mature individuals and their locations upon death implies that a taxonomically broad reason for death is needed. It was concluded that multiple mass strandings had taken place, with a possible cause of this being the ingestion of harmful algal blooms (HABs). These blooms have been associated with strandings before (see references 37-41 in the paper) and it was therefore suggested that the toxins from these HABs may have been the cause of the strandings. However, the researchers cannot say for sure if this was the case as no algal cell fragments were found in the sediments but hey do not eliminate the possibility.
This site, now christened Cerro Ballena (‘whale hill’), is an important and amazing discovery which will hopefully provide useful research in the future. It is now regarded as one of the densest fossil sites, especially for whales and extant marine mammals, and it is likely that hundreds of other specimens remain in the area to be excavated. I hope that the University of Chile can establish a research group to carry out this work.
Full citation of article: