Those Sponges Are Actually Bryozoans – #365papers – 2017 – 6

#365papers for January 6, 2017

Muricy, Domingos, Tavora, Ramalho, Pisera, and Taylor, 2016, Hexactinellid sponges reported from shallow waters in the Oligo-Miocene Pirabas Formation (N Brazil) are in fact cheilostome bryozoans: Journal of South American Earth Sciences, v. 72, p. 387-397.

What’s it about?

This paper is about some incorrectly identified fossils from Brazil. Sponges are animals that survive by filter feeding. Hexactinellid sponges have a skeleton made of glass and are only found at great depths, so it was interesting with previous authors found hexactinellid sponges in rocks deposited in shallow waters.

The authors of this paper took the sponge fossils and looked at them closely under a scanning electron microscope and realized that the earlier identification was incorrect and that these were in fact bryozoans, which are colonies of tiny filter-feeding organisms that can live in a structure that is shaped similar to that of sponges.

Why does it matter?

It’s easy to mis-identify a fossil. This paper shows the importance of applying newer technology to study fossils that had been collected even a hundred years ago.

This paper also showed, likely to the relief of some researchers, that there are not any shallow water hexactinellid sponges. Whew.

Why did I read this?

This semester I’m teaching a course that involves invertebrate paleontology. Bryozoans are difficult for me to teach about because they are so tiny, so on the day I found this paper, I was looking for papers on bryozoans to share with my class. Not sure yet if this one will make the cut…