This week, a group of Chinese, Japanese and US researchers published a paper on a tiny sea anemone-like fossil which was found in the sediments of the Kuanchuanpu Formation, in Southern China. In the paper, Tiny Sea Anemone from the Lower Cambrian of China, the authors used electron microscopy and computer-aided microtomography to analyze the soft-bodied microfossil which measures about a half of a millimeter in size.
Below is figure 2 from the paper which shows the paratypes of the tiny Eolympia pediculata.
From the Abstract:
Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first major branch of the Cnidaria. Because of difficulties in taxonomic assignments owing to imperfect preservation of fossil cnidarian candidates, little is known about forms ancestral to those of living groups.
Methods and Findings
We have analyzed the soft-bodied polypoid microfossils Eolympia pediculata gen. et sp. nov. from the lowest Cambrian Kuanchuanpu Formation in southern China by scanning electron microscopy and computer-aided microtomography after isolating fossils from sedimentary rocks by acetic acid maceration. The fossils, about a half mm in body size, are preserved with 18 mesenteries including directives bilaterally arranged, 18 tentacles and a stalk-like pedicle. The pedicle suggests a sexual life cycle, while asexual reproduction by transverse fission also is inferred by circumferential grooves on the body column.
The features found in the present fossils fall within the morphological spectrum of modern Hexacorallia excluding Ceriantharia, and thus Eolympia pediculata could be a stem member for this group. The fossils also demonstrate that basic features characterizing modern hexacorallians such as bilateral symmetry and the reproductive system have deep roots in the Early Cambrian.
If you liked this image, the paper includes several more photos, as well as, short movies of the micro-CT imaging. This article is freely available for you to read, comment on and rate.