Maculicorpus
Maculicorpus is a fossil genus, potentially a placozoan, from the Middle Triassic of Germany. If its identity is correct, it is the only placozoan known from the fossil record. It comprises a single known species, Maculicorpus microbialis.
Discovery
Maculicorpus is known from a microbialite bed discovered in the Troistedt Quarry near Weimar, as part of the Meißner Formation. The microbialite has been dated to the late Anisian to early Ladinian.
Description
The specimens referred to Maculicorpus appear as flat patches, brown to ochre in color, varying between and in diameter. The outline is irregular and varies in overall shape from circular to elongate, fan-shaped or multi-lobed. The holotype, in length, is constricted in the middle, appearing as an aggregate of a larger, irregularly rounded portion and a smaller elliptical one. Maculicorpus is larger than any modern-day placozoan.
Classification
A study on the taphonomy of a modern day placozoan, Trichoplax, cast uncertanity on the placozoan affinity of Maculicorpus due to the fact that placozoans appear to disintegrate into their component cells upon death in a manner inconsistent with the observed preservation of Maculicorpus. It was stressed more evidence for placozoan affinity is necessary, and that if the genus is a placozoan it must have been unlike modern forms in certain ways.
Works cited
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