Tuesday, June 23, 2015

Drotops megalomanicus trilobite from Morocco

I'm not sure why but this trilobite makes me giggle a little bit when I hold it. Droptops megalomanicus is the largest trilobite species that I own and it is really cool to look at.This specimen comes from Jebel Mrakib near Alnif in the Tafilalet region of Morocco. The sheer size is rather amazing and reminds me of the Phacops rana trilobites that come from the Silica Shale. However the P. rana from the Silica Shale would get to be around 3-4" in length for a larger specimen while the one pictured below is 6-7" and they could get up to 8" in length.

I like how the trilobite "sits" on the rock. It is not perfectly prone, the pygidium and part of the thorax are slightly twisted and the whole body is slightly flexed. It lends more of an air of authenticity to me whereas something that is perfectly shaped and lain out looks more fake. Specimens of this species are commonly faked and I have seen plaster casts glued onto rock bases being sold as authentic.

Another special feature of this specimen is that the hypostome is preserved. You can see fine lines that are preserved on the hypostome and cephalon underside. These are called terrace ridges (because they sometimes look like contours on a topographical map) and are a good indicator that the specimen is authentic. Fakes do not preserve this level of detail.

Based on the paper by Bernd Kaufmann, "Facies, stratigraphy and diagenesis of Middle Devonian reef-and mud-mounds in the Mader (eastern Anti-Atlas, Morocco)." Acta Geologica Polonica 48 (1998): 43-106., Drotops megalomanicus is from the earliest part of the Givetian stage of the Devonian. He notes that D. megalomanicus is "abundant" within a layer below the Aferdou mud mound feature on Jebel Mrakib.

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