Trilobite ID

[Kane]

Pygidium found in the Hamilton Gp (I don't have anything more specific as the location from where this was found contains all materials trucked in from different parts of the region). I suspect it is a Proetus, and if so, not entirely sure which species.

At present, it looks very similar to some of the specimens in the Proetus plates in Stumm, E. (1953) "Trilobites of the Devonian Traverse Group of Michigan." Contributions From the Museum of Paleontology, UM 10.6: 101-57. My best uneducated guess is P. alpenensis.

1. Is this the pygidium of a Proetus and, if so

2. Any clue as to the species (alpenensis, maybe?)

Grateful in advance for the help!

[Raggedy Man]

CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY

UNIVERSITY OF MICHIGAN

VOL. XI NO. 6, pp. 101-157 (12 pk., 1 map) MARCH 25, 1953

TRILOBITES OF THE DEVONIAN

TRAVERSE GROUP OF MICHIGAN

BY ERWIN C. STUMM

UNIVERSITY OF MICHIGAN PRESS

ANN ARBOR

Plate 1, figure 3

Proetus (Crassiproetus) alpenensis

Looks close to me as well. Let's see what others have to say.

Nice find

Best regards,

Paul

[Northern Sharks]

Crassiproetus crassimarginatus is known from Arkona

[Kane]

Thanks. Stumm's article was my first stop for comparison.

@Northern Sharks: my only uncertainty at this point is that this specimen is appearing with rock that isn't exactly like the Arkona or Widder Fms. Although some have tentaculids and spirifers (not in itself enough to declare "Hamilton Gp" so I should have placed a "?" next to that), it appeared in rock with a heavier preponderance of iron oxide staining AND Leptaena (so not suggestive of the chunky, orange-stained, and heavily spiriferid portion of the Widder). There's very little to no coral in these piles apart from some tell-tale rocks mixed in from the Dundee (which are quite markedly different in composition and texture). This Proetus is appearing with some very large brachs (not spirifers).