I spent today revisiting a farm ditch I last explored back in March of this year. It was there that I found some pygidia of Odontocephalus n. sp., along with occasional pygidia of the typical pre-Hamilton Gp Devonian proetid cockroaches (Pseudodechenella sp., Crassiproetus sp.), and one "Mystrocephala" (in quotations because it was discovered that this genus name is already occupied by a butterfly or some-such). Anyhow, this material is quite miserable, ugly, and by turns barren or low sedimentation rate, coral encrusted, bituminous, cherty, chalk-cherty, mottled, occasionally diagenetically reworked, etc. Most of the fossils are silicified, which is fairly typical of many horizons in the Amherstburg, Lucas, and even Dundee Fms. Finds are uncommon in this crappy material. I should also mention that the skies opened up, so that cut my time short. Despite all this series of unfortunate incidents, I still managed to find a nice bit of trilobite treasure. I was initially wrestling in identifying this Dalmanitid, whether it was a Trypaulites. However, the images in Ludvigsen and Lespérance were not exactly satisfactory to pin down the identification. I even dug into my Hall & Clarke plates, but it wasn't a good match. The age of the material ruled out Anchiopsis, as the material is younger than Bois Blanc Fm (and, it doesn't have an occipital spine, nor even an incipient one). It obviously is not an Odontocephalus as it does not have the typical "cow-catcher." So, where does this one fit, given the rather long and exaggerated anterior process? Thankfully, a trilobite expert and friend of mine (SM) provided his opinion: Neoprobolium n. sp. Although it lacks the trident of N. tridens or that of N. nasutus, it may in fact be a match as none other seem to fit. If so, a first in Ontario of this rare Dalmanitid which is reported in New York. Between two possible new species of Odontocephalus, and an Amherstburg Fm trochurine lichid, I am adding to the list of undescribed Devonian trilobites of Ontario. If only someone was out there to write these up, as lengthy and work intensive a process as that is. UPDATE: So I went back to the same site again hoping for lightning to strike twice. It kind of did. Apart from the usual suspects (fragments of the trilobites I generally find in this material), a new species for me: This one is a large specimen, too, at about 7.5 cm (about 3 inches) wide. Note the rounded tubercles. This is an exceptionally rare dalmanitid in Ontario. It belongs to the genus of Anchiopsis and the species is tuberculatus. These are simply almost never found around here, and is shown in Hall & Clarke's plates, and described in the Jeffersonville limestone by Stumm (1954). I do have the negative, but am unsure if the eyes will be in there (hopefully).
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Kane Faucher
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February 2024
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