100 million-year-old fairy shrimp reproduced without sex, rare fossils reveal

[Judi Lynn]

By Cameron Duke published 1 day ago

Cretaceous period fossils indicate female fairy shrimp had no need for males.

Ancient female fairy shrimp may have gotten along just fine without males. Researchers studying Cretaceous-period freshwater fossils in the Koonwarra fossil bed in southern Australia have described a new species of now-extinct freshwater shrimp (Koonwarrella peterorum) whose females likely reproduced without sex — a phenomenon known as parthenogenesis, which is a type of asexual reproduction.

Parthenogenesis is the spontaneous development of an embryo from an unfertilized egg. It's known to occur in both plants and animals, although it is thought to be extremely rare. Some species, such as whiptail lizards, reproduce exclusively through parthenogenesis, but some sexually reproducing species have been known to reproduce parthenogenetically, as in the case of two fatherless California condors reported in the Journal of Heredity in 2021.

"As far as we can tell, [parthenogenesis] is unknown in the fossil record of fairy shrimp," study co-researcher Thomas Hegna, an assistant professor of paleontology at the State University of New York (SUNY) at Fredonia, told Live Science. Although parthenogenesis has been spotted in modern brine shrimp, this is the first time it has been recognized in freshwater varieties.

This new species was identified from 40 individual fossils across the Koonwarra fossil bed, a paleontological site dating to the Aptian age (125 million to 113 million years ago) that's rich in fossils, including feathers from avian-line dinosaurs, as well as bony fish and invertebrates such as these fairy shrimp. The fossils themselves are housed in the paleontological collections of the Melbourne Museum in Victoria, Australia.

More:
https://www.livescience.com/fossil-fairy-shrimp-reproduction?utm_source=notification

[bucolic_frolic]

1. "Honey, I don't need you!" replaces "I have a headache"

Talk about men being expendable.