93 million years in the past, weird, winged sharks swam in the waters of the Gulf of Mexico. This newly described fossil species, referred to as Aquilolamna milarcae, has allowed its discoverers to erect a new household. Like manta rays, these ‘eagle sharks’ are characterised by extraordinarily lengthy and skinny pectoral fins reminiscent of wings. The specimen studied was 1.65 meters lengthy and had a span of 1.90 meters.
Aquilolamna milarcae had a caudal fin with a well-developed superior lobe, typical of most pelagic sharks, similar to whale sharks and tiger sharks. Thus, its anatomical options thus give it a chimeric look that mixes each sharks and rays.
With its massive mouth and supposed very small enamel, it should have ate up plankton, in keeping with the worldwide analysis crew led by Romain Vullo of the CNRS.
Scientists have recognized just one class of massive plankton feeders in Cretaceous seasuntil now: a group of massive bony fish (pachycormidae), which is now extinct. Due to this discovery, they now know that a second group, the eagle sharks, was additionally current in the Cretaceous oceans.
The whole specimen was discovered in 2012 in Vallecillo (Mexico), a locality yielding remarkably preserved fossils. This web site, already well-known for its many fossils of ammonites, bony fish and different marine reptiles, is most helpful for documenting the evolution of oceanic animals.
In addition to shedding gentle on the construction of Cretaceous marine ecosystems, the discovery of eagle sharks reveals a new, hitherto unsuspected, aspect of sharks’ evolutionary historical past.
Reference: “Manta-like planktivorous sharks in Late Cretaceous oceans” by Romain Vullo, Eberhard Frey, Christina Ifrim, Margarito A. González González, Eva S. Stinnesbeck and Wolfgang Stinnesbeck, 18 March 2021, Science.