PHYLOGENETIC ANALYSIS OF THE FOSSIL SHRIMP-LIKE DECAPODS (DENDROBRANCHIATA, STENOPODIDEA AND CARIDEA) FROM THE SOLNHOFEN LAGERSTÄTTE

The Solnhofen Lagerstätte is one of the first good fossil records of the shrimp-like decapods. Though the phylogeny of these taxa has been studied to a limited extent, only extant forms have been included in the analyses. Over half of the fossil shrimp species from the Solnhofen Lagerstätte and several extant shrimp species have been coded based upon morphological characters. A phylogenetic analyses has been performed based on the resulting matrix. The Solnhofen fossils and preserved extant samples that have been observed are curated in the United States National Museum, Smithsonian Institution, the Carnegie Museum, and a private collection. Importantly, many holotypes and additional specimens of Solnhofen shrimp taxa were examined at the Bayerische Staatssammlung für Paläontologie und Geologie in Munich. Inclusion of fossil representatives in shrimp phylogeny will offer new insight regarding the phylogeny of the entire decapod order.

Preliminary results do not support the status of the family Penaeidae and the genera Acanthochirana and Antrimpos as natural groups. They indicate that carapace groove and spine characters are not phylogenetically significant for the fossil groups, partially due to their poor preservation. The appendage characters, on the other hand, seem to exhibit a high degree of consistency for each group which could be useful for developing hypotheses of group divergence based on adaptative physiology. The results also seem to indicate that the dendrobranch general model is indeed the plesiomorphic form for the shrimp-like decapods.

This work was funded by NSF EAR 1223206 to Schweitzer and Feldmann and a Kent State University Department of Geology Amoco Alumni grant to Sudarsky.