The Bandringa shark, is likely on of the earliest close relatives of modern sharks. Bandringa sharks were a bottom-feeding predator that inhabited a river delta system in what is now the Upper Midwest. Juveniles were only 4-6 inches long with adults reaching 10 ft, with an elongated snout up to half their body length.
Until recently
paleontologists believed there were two species, Bandringa
rayi and B. herdinae, one of
which lived in freshwater swamps and rivers, and another that lived in shallow
oceans. However, after 24 individual fossils were reevaluated, it was concluded
that Bandringa was a single species,
living in both fresh, brackish, and salt water at various life stages.
The Badringa fossil were preserved along with
fossilized egg cases and juvenile sharks in the same sediments. This reveals a
310-million-year-old shark nursery, the earliest known shark nursery.
Lauren Cole Sallan & Michael I. Coates. 2014. The long-rostrumed elasmobranch Bandringa Zangerl, 1969, and taphonomy within a Carboniferous shark nursery.Journal of Vertebrate Paleontology, vol. 34, no. 1, pp. 22-33; doi: 10.1080/02724634.2013.782875
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