This week's fossil is PRI 28297, Echinocaris punctata (Hall, 1863). It is a "hypotype," which is a fancy technological word for a specimen of an already-named species that was illustrated (or "figured" in science-speak) in a publication that extends the knowledge about the species (in other words, the picture can't just be a photograph in a coffee-table book). Our "type and figured collection" contains many hypotypes, which are in many ways just as important as type specimens. This particular hypotype was illustrated and discussed in the very short paper "New and interesting fossils from the Devonian of New York," by Axel Olsson in Bulletins of American Paleontology number 23, in December 1912. The specimen was worthy of mention because it was found in a new "horizon," that is a layer of fossils that it had never been found in before. This one is from the McGraw or University Quarry on Cornell Campus, from the Upper (or Late) Devonian, Genesee Group, Ithaca Formation - which sounds (and is) really local, and in essence means about 400 million years old.
The species: This fossil is a kind of animal that you might never have heard of before - a phyllocarid crustacean. A phyllocarid (the living ones are called leptostracans) is a very small shrimp-like critter that has a laterally flattened, bivalved carapace enclosing jointed feathery legs for swimming, stalked compound eyes, and a tapering abdomen ending in a forked tail. Phyllocarids live in mud or sometimes in the plankton, along with copepods which they closely resemble. The oval shape that you can see on the rock (here only about an inch long) is the carapace of the phyllocarid - that's the equivalent of the main body of a lobster (minus its tail, legs and tentacles). The sharp "keel" on the fossil is probably the junction of the two carapace valves. There is no widely known common name for these tiny creatures, but the name "sea fleas" has been used. Modern phyllocarids filter-feed, that is, they strain organic particles from the seawater for food using their feathery appendages. There are only about 40 species of living phyllocarids. The living phylocarid Nebalia bipes is illustrated here (photograph by Hans Hillewaert Lycaon, via Wikimedia Commons).
The author: Axel Adolf Olsson (1889-1977) was a student of Cornell Professor Gilbert Harris (PRI's founder and first director), earning an Associate degree in 1913 (so he was a student when he published the paper discussed here). He spent most of his career studying fossil mollusks as a paleontologist in the petroleum industry, and retired to Florida in the 1950s. He served on the Board of Trustees at PRI, and was its president three separate times in the 1930s, 1940s, and 1960s. He was a strong supporter of PRI relocating to the south, because many of the fossils in its collection, including most of those studied by Harris, are from the southeasterm coastal plain.
The species: This fossil is a kind of animal that you might never have heard of before - a phyllocarid crustacean. A phyllocarid (the living ones are called leptostracans) is a very small shrimp-like critter that has a laterally flattened, bivalved carapace enclosing jointed feathery legs for swimming, stalked compound eyes, and a tapering abdomen ending in a forked tail. Phyllocarids live in mud or sometimes in the plankton, along with copepods which they closely resemble. The oval shape that you can see on the rock (here only about an inch long) is the carapace of the phyllocarid - that's the equivalent of the main body of a lobster (minus its tail, legs and tentacles). The sharp "keel" on the fossil is probably the junction of the two carapace valves. There is no widely known common name for these tiny creatures, but the name "sea fleas" has been used. Modern phyllocarids filter-feed, that is, they strain organic particles from the seawater for food using their feathery appendages. There are only about 40 species of living phyllocarids. The living phylocarid Nebalia bipes is illustrated here (photograph by Hans Hillewaert Lycaon, via Wikimedia Commons).
The author: Axel Adolf Olsson (1889-1977) was a student of Cornell Professor Gilbert Harris (PRI's founder and first director), earning an Associate degree in 1913 (so he was a student when he published the paper discussed here). He spent most of his career studying fossil mollusks as a paleontologist in the petroleum industry, and retired to Florida in the 1950s. He served on the Board of Trustees at PRI, and was its president three separate times in the 1930s, 1940s, and 1960s. He was a strong supporter of PRI relocating to the south, because many of the fossils in its collection, including most of those studied by Harris, are from the southeasterm coastal plain.
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