LSCHNELLE Posted June 5, 2022 I agree that it's an odd shark. Having teeth shaped more like bullet tips than knives. Certainly, it's diet was significantly different from two of its genus-level competitors - Ptychodus marginalis (during Turonian) and Ptychodus latissimus (during Turonian & early Coniacian). I have not found one in Central Texas that was extracted from strata older than the Basal Atco lag deposits. 1 Link to comment
ThePhysicist Posted June 5, 2022 (edited) 17 hours ago, LSCHNELLE said: I have not found one in Central Texas that was extracted from strata older than the Basal Atco lag deposits. I'm fairly confident that this is middle Turonian. I haven't seen much discussion on the geology of POC, and I've questioned the label of "Eagle Ford." But recently, I've evaluated evidence that supports this: the lithology, presence of Cameleolopha bellaplicata, and a somewhat disparate fauna from the Atco. Edited June 5, 2022 by ThePhysicist Link to comment
LSCHNELLE Posted June 6, 2022 (edited) 7 hours ago, ThePhysicist said: I'm fairly confident that this is middle Turonian. I haven't seen much discussion on the geology of POC, and I've questioned the label of "Eagle Ford." But recently, I've evaluated evidence that supports this: the lithology, presence of Cameleolopha bellaplicata, and a somewhat disparate fauna from the Atco. I have found the Lopha lugubris (not the L. bellaplicata bellaplicata zone you reference). I think that one is Upper Turonian. It was is in several places in Central Texas in the South Bosque Member of the Eagle Ford. So far, no obvious P. whipplei from that zone here. There was one pathologic Ptychodus that might have been a "short" crowned P. whipplei. What is present there is some P. anonymous and P. marginalis with more commonly the new Ptychodus species that should be brought to press this year. Above that, it seems that the Basal Atco lag has scoured out some of the Upper Turonian Eagle Ford with an uncomformity. Edited June 6, 2022 by LSCHNELLE Link to comment
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