Merry Christmas!

An extremely belated Happy Fossil Day!

I'm exactly two months late, but I love all of the artwork associated with this wonderful day, so here goes:
Happy Fossil Day!

No. 7. Isotelus megistos

"No. 7. Isotelus megistos, with cotemporary fossils, Adams County, Ohio. Restored from fragments Nos. 1 to 5 inclusive, by Locke." - thus reads the label on the back of my favorite specimen in the entire collection. It's a plaster reconstruction. It's a little bigger than it should be (but only a little). It has plaster casts of other critters that lived at the same time surrounding it like garnishes around a Thanksgiving turkey. I love it. No matter what kind of beautiful specimens I come across, I always fall back on my old favorite - No. 7.

Lobsters vs. crabs - a crustacean showdown!

In cataloging some reprints here at the museum, I came across a guide leaflet from the American Museum of Natural History (AMNH) from 1929. It is a small leaflet entitled, "Outposts of the Sea," by Roy Miner, and it details some aspects of intertidal and shallow sea life. It also has an awesome subtitle, "The animals of the tidal realm - Marine hosts that today assail our continental borders, endeavoring to repeat the conquest attained ages ago by the ancestors of the present land-animals." How awesome is that? I am now envisioning an army of lobsters crawling onto the beach with their chelae (claws) raised in protest at our occupation of the land.
Roy Waldo Miner (curator of Marine Life at the AMNH) wrote an informative and enlightening look at the shallow seas that surround our country and the creatures who inhabit it. He touches on all of the major groups including arthropods, echinoderms, molluscs, cnidarians, and an assortment of "worms".

What initially caught my eye about this leaflet is the drawing on the cover that shows a lobster attempting to grab a crab in its claws. My first thought was that this was a cute bit of whimsy, but not knowing much about lobster and crab interactions I left it at that. There is another picture in this leaflet that shows the same type of scene: a photograph of a diorama in which a lobster is attempting to "catch" a crab.

Curiosity finally getting the better or me, I asked our resident crab expert about the paper. Much to my surprise, I learned that the American lobster (Homarus americanus) does indeed catch and eat crabs (notably Cancer borealis and C. irroratus). A recent paper published by J. M. Hanson found that half of a lobster's diet (this being a lobster with a carapace of at least 4cm) was made up of rock crabs (Cancer irroratus). While it has been suggested (see Drew, 2011) that the Cancer crabs are evolving thicker, stronger carapaces in the eternal arms race of the sea, my money is definitely on the lobster winning in the lobster-crab showdown.

Drew, D. J. 2011. "A Comparative Morphometric Analysis of Cancer borealis Stimpson, 1859 and C. irroratus Say, 1817 (Decapoda: Brachyura: Cancridae) in the Northwest Atlantic Ocean." Bulletin of the Peabody Museum of Natural History, vol. 52, no. 2, p.241-254.

Hanson, J. M. 2009. "Predator-prey interactions of American lobster (Homarus americanus) in the southern Gulf of St. Lawrence, Canada." New Zealand Journal of Marine and Freshwater Research, vol. 43, no. 1, p.69-88.

Snorkeling the past

A friend of mine is on her way to China to study the end-Permian mass extinction. Follow her exploits here.

Genus of the day!

Occasionally I come across an awesome genus. Not necessarily amazing in appearance, not always really cool in its mode of life, but definitely bearing an intriguing name. Today's come from the nautiloids. Mysterioceras - an Ordovician orthocerid nautiloid from Tasmania and the former USSR. We don't actually have any in our collection; I was cataloging a specimen of Campyloceras, and Mysterioceras is on the same page in the Treatise.

snails in the desert

When I think of deserts, I think of sand, heat, and aridity. Now, I know this isn't true for all deserts, but I think it's fair to describe the Sahara Desert in this way. What I don't think of when I think of deserts are snails - small molluscs who have a shell and an operculum (think of it as the front door of the snail's house that he can close as needed), but who also need to keep their muscular foot moist.
I was a little surprised to come across some snails from the Kurkur Oasis in Egypt here in the collection. Okay, so they're terrestrial (good because there's no ocean in the Sahara Desert) and they're from the Pleistocene (also good because there wasn't an ocean there at this point in time either), and they lived in an oasis (which by its very name suggests there is some moisture). But they're still snails. How do snails cross an 'ocean' of sand to find these oases? Darwin suggested passive dispersal that was probably carried out by birds, and this explanation has been fairly well accepted ever since.
More recently human movements and fishery activities have further spread certain organisms, but this is almost certainly not the case for these Pleistocene snails. At any rate, these snails made it into the desert and then back across the ocean to Connecticut.

 As described by the collector, Egbert Leigh, Jr., "this fauna bears a striking resemblance to a fauna in a small, nearly stagnant cove of Lake Carnegie, Princeton, New Jersey" (p.514, Desert and River in Nubia, Butzer and Hansen, 1968).
So, there you have it - stagnant pools in the middle of the desert.

A little bit of whimsy

I am generally fairly serious in this blog, but every now and then a fossil comes along that makes me giggle. Today it came from Florida. More specifically, it came from the Pleistocene deposits south of Lake Okeechobee. These deposits are renowned for the molluscan fauna that is present in them (and if you want to check out more of the molluscan fauna, I recommend Heilprin's Explorations on the west coast of Florida and in the Okeechobee wilderness from 1887 - some of the taxonomic names have been revised, but it is still a great overview).
 Today's specimen comes from a lot of five Trivia pediculus collected by a CT resident, and then donated to the Peabody Museum in 1947. Four of the specimens were typical Trivia specimens. The fifth had been colonized by two barnacles.

YPM.069233 - Trivia pediculus

Locke's Cabinet

Dr. John Locke was a professor in Cincinnati between 1835 and 1856. He was interested in several subjects ranging from geology and hydrology to electricity and magnetism. Locke invented many things, but his most significant invention was an electro-chronograph developed for the U.S. Coast Survey in 1848.

According to the American National Biography, "When attached to the second hand of a clock and connected to a telegraphic circuit, the electro-chronograph made clocks beat simultaneously all along the telegraph line and produced a paper strip chart that recorded events with an accuracy of one hundredth of a second. In an era before the development of time standards, this instrument was invaluable for determining longitudes and for precise observations in physics, geophysics, and astronomy. He received an award of $10,000 from Congress for his invention"
Of more interest to me is Dr. Locke's fossil cabinet. He was active in local scientific societies, and he even described a few species of trilobites (1838, "Prof. Locke's geological report, communicated by the Governor to the General Assembly of Ohio. December, 1838." Second Annual Report on the Geological Survey of Ohio, p.201-286. [in which he describes Isotelus maximus], and 1843, "Notice of a new trilobite, Ceraurus crosotus." American Journal of Science. 44: 436). In our collection we have several plaster casts of specimens from Dr. Locke's cabinet. I intend to photograph and include these here on this blog.

So, first up is Number 39. Strophomena alternata with an encrinite [Streptaster vorticellatus] attached, 6 miles of Cincinnati. (YPM 112989).