This is Mazon Monday post #120. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
-----------------------------------------------------
Lobetelson mclaughlinae is one of the few remaining shrimp species we haven't looked at. It was described in 2006 by Frederick Schram, who described many of the Mazon Creek crustaceans. The description was published in the paper "Lobetelson mclaughlinae, a new genus and species of belotelsonid malacostracan from the Pennsylvanian of the Mazon Creek area".
Lobetelson mclaughlinae n. gen., n. sp. from the well-known Mazon Creek faunas of the Pennsylvanian (Carboniferous) of northeastern Illinois, USA, shares features in common with Belotelson magister (Packard, 1886), such as eight pairs of uniramous reptant thoracopods and a generalized caridoid body plan. The similarities are such that specimens of both species originally were mixed in museum and private collections of the fauna. However, L. mclaughlinae n. gen., n. sp. is distinguished by its more gracile thoracopods, extremely long rostrum (at least equal in length to the carapace), and a wide tail fan formed by broad lobate uropodal rami. In contrast, B. magister is now understood to possess more robust thoracopods, with a relatively short rostrum, and very styliform uropodal rami.
This species does not appear in the ESCONI "Creature Corner", the "Keys to Identify Mazon Creek Animals", or the "Richardson's Guide to Mazon Creek Fossil Fauna" as it was described after all those books were written.
Here is what "The Mazon Creek Fossil Fauna" has to say.
Lobetelson mclaughlinae Schram, 2006
The Lobetelson mclaughlinae form was not classified as a separate species until recently when a significant number of specimens presented a unique and defining set of characteristics. For a while, it was simply known as the gracile form of Belotelson magister. Now it is the one and only member of the genus Lobetelson. This species is still closely related to B. magister with which it shares many features, most notably a generalized body plan.
The carapace is smooth, about half the length of the animal, with an optic notch. Its prominent rostrum averages about the same length as the carapace and is sharply pointed. The eyes are stalked and the antennae are well-developed. The thoracopods are thin and stilt-like. The pleopods form a prominent tail fan of long, broad paddles.
Because L. mclaughlinae had thin legs, it was likely a poor walker, but with wide tail fins (uropods), it would have been a good swimmer and an active scavenger/predator.
Photos
From "The Mazon Creek Fossil Fauna"
