Otavia

The affinities of these fossils, along with other paleontological evidence for Precambrian sponges, are disputed.

Some researchers propose that Otavia antiqua may have evolved over 100 million years earlier than previously thought, which supports the ‘molecular clock’ predictions that sponges were among the first animals to appear.

Some scientists theorized that the burial of Otavia may have actually contributed to carbon burial and to the rising in oxygen levels during the Neoproterozoic. Furthermore, Otavia antiqua fossils are present in strata both before and after major glaciation events, indicating the organism may have survived the extreme conditions of ‘Snowball Earth’.

Discovery and Naming

Some of the earliest evidence of animal evolution can be found in fossils from the Ediacaran period, which show early diversification of precambrian animals.

In the Namibian Otavi and Nama groups, samples of black limestone were collected, and dissolved in acetic acid. This produced over a thousand individual specimens of a small sponge-like fossil.

A 2012 paper, Brain et al. (2012), described these specimens, placing them in the genus which they named 'Otavia', after the Otavi group which many of the samples that specimens were found in were from, and gave it the species name 'antiqua'.