The scientists published their findings in the journal Proceedings of the National Academy of Sciences. This relic, with its coiled stalk and large, horseshoe-shaped nucleus is reminiscent of the modern-day Vorticella, a genus of protozoa. Vorticella have stalked, inverted bell-shaped ciliates that are placed among the peritrichs. Each cell has a separate stack anchored onto the substrate that contains a myoneme, a contractile fibril. Once stimulated, it shortens, causing the stalk to coil like a spring. Many Vorticella species live in freshwater ponds and streams. The specimen is unknown in the fossil record. Soft-bodied organisms, like protozoans, aren’t usually well preserved as fossils. Egg casings of leeches and their kin are another matter. The walls quickly harden from a protein and sugar-rich mucus secreted by invertebrates. This egg, produced by Hirudo medicinalis, the medicinal leech, can trap soft-bodied organisms that would quickly degrade. Although a few teams have previously described small fossils stemming from spores and microorganisms entombed in egg cases, the cocoons have been largely ignored by paleontologists and could source as a source of microbial fossils. Reference: “Triassic leech cocoon from Antarctica contains fossil bell animal” by Benjamin Bomfleur, Hans Kerp, Thomas N. Taylor, Øjvind Moestrup and Edith L. Taylor, 3 December 2012, Proceedings of the National Academy of Sciences.DOI: 10.1073/pnas.1218879109
