sharko69 Posted December 9, 2017 Share Posted December 9, 2017 Found this beauty a couple of weeks ago. I have identified it as P. atcoencis because of the chevron pattern but the crown is very low and it has more ridges then teeth I have previously found. Thoughts? Link to comment Share on other sites More sharing options...
Brittle Star Posted December 9, 2017 Share Posted December 9, 2017 It is wonderful whatever it is. 1 Never ask a starfish for directions Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted December 9, 2017 Share Posted December 9, 2017 Mmm. Ptychodus marginalis, maybe? Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
JarrodB Posted December 9, 2017 Share Posted December 9, 2017 Perfect! Link to comment Share on other sites More sharing options...
Ludwigia Posted December 9, 2017 Share Posted December 9, 2017 I don't know much about teeth, but I know what I like Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Miocene_Mason Posted December 10, 2017 Share Posted December 10, 2017 Awesome find! All the ones in my collection are dinged up and sun bleached, the complete beautiful ones must be super rare! “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
sharko69 Posted December 10, 2017 Author Share Posted December 10, 2017 14 hours ago, WhodamanHD said: Awesome find! All the ones in my collection are dinged up and sun bleached, the complete beautiful ones must be super rare! Thank you. I have around 400 Ptychodus and have only a handful in this condition. It is always fun to find teeth in great condition. I do however really like when you can see the wear caused by the animal eating. I think they tell a special story as well. 1 Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 13, 2017 Share Posted December 13, 2017 Do you know which geologic formation and/or member it came from? Was it Atco, or Eagle Ford: Kamp Ranch (S. Bosque), or Arcadia Park (flaggy member)? Or, was it loosened from the rock matrix? Link to comment Share on other sites More sharing options...
abyssunder Posted December 13, 2017 Share Posted December 13, 2017 There is a precious document in the pinned "Ptychodus Id Quick Guide" topic, which might help. 1 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 13, 2017 Share Posted December 13, 2017 Without further information on the strata, I would lean toward Ptychodus mammillaris due to flattened crown. Not P. marginalis, since no concentric ridges pattern. P. atcoensis (only from Atco Formation) and others with moderate crown height typically have a more rounded or conical crown. Usually, P. atcoensis chevron pattern crosses most or all ridges. Yet, it might still be a variation of P. atcoensis if from Atco Formation. 1 Link to comment Share on other sites More sharing options...
sharko69 Posted December 14, 2017 Author Share Posted December 14, 2017 19 hours ago, LSCHNELLE said: Do you know which geologic formation and/or member it came from? Was it Atco, or Eagle Ford: Kamp Ranch (S. Bosque), or Arcadia Park (flaggy member)? Or, was it loosened from the rock matrix? Sorry. Forgot to add. Eagle Ford, Sherman. Was found loose. 18 hours ago, abyssunder said: There is a precious document in the pinned "Ptychodus Id Quick Guide" topic, which might help. Thank you. Yes, that is a great reference that I use with regularity. Still left me with a few questions on this identification. Link to comment Share on other sites More sharing options...
sharko69 Posted December 14, 2017 Author Share Posted December 14, 2017 Attached is a P. atcoensis from the same area in the Eagle Ford/ Atco contact. Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 14, 2017 Share Posted December 14, 2017 22 minutes ago, sharko69 said: Sorry. Forgot to add. Eagle Ford. Thank you. Yes, that is a great reference that I use with regularity. Still left me with a few questions on this identification. This is not P. atcoensis if from Eagle Ford. P. mammilaris has a flattened crown and from 7 to 10 ridges. This tooth fits that description. The chevron folds on the two ends can occur as an irregularity on P. mammilaris, but usually the ridges are straight across. On other Eagle Ford Ptychodus, the ridges often extend to the edges of the margins. These stop near the center of the margin. 1 Link to comment Share on other sites More sharing options...
doushantuo Posted December 14, 2017 Share Posted December 14, 2017 FROM: bricenoptycompletsatcoens13358-013-0053-3.pdf 2 Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 14, 2017 Share Posted December 14, 2017 31 minutes ago, doushantuo said: FROM: bricenoptycompletsatcoens13358-013-0053-3.pdf doushantuo: Thanks for sharing that PDF article. I have not been able to obtain a copy of it yet. The tooth you took a snapshot of appears to be close to sharko69 images. So, if it is from the Atco contact and not the Kamp Ranch/South Bosque, then definitely P. atcoensis. If not, then P. mammilaris. 2 Link to comment Share on other sites More sharing options...
doushantuo Posted December 14, 2017 Share Posted December 14, 2017 From a classic and classy study of P. mediterranensis: line drawing of specimen,1/4 nat.size 1 Link to comment Share on other sites More sharing options...
siteseer Posted December 16, 2017 Share Posted December 16, 2017 On 12/14/2017 at 7:48 AM, LSCHNELLE said: doushantuo: Thanks for sharing that PDF article. I have not been able to obtain a copy of it yet. The tooth you took a snapshot of appears to be close to sharko69 images. So, if it is from the Atco contact and not the Kamp Ranch/South Bosque, then definitely P. atcoensis. If not, then P. mammilaris. I remember when I met Bruce Welton back in 1994 (he and Roger Farish) was doing signings at shows, promoting the book), I was talking to him about his years collecting in southern California. A collector was behind me and he wanted an ID on an oddball Ptychodus (something like this one showing features of two different species). Bruce kind of sighed and muttered something about Ptychodus not always being easy to Identify to species. With this tooth if pressed for one ID, I would say P. mammilaris because P. atcoensis has such a distnct cusp, appearing to have grown vertically out of the marginal area like a bulb. The tooth in question has a cusp that has a more gradual slope to it from one angle. I would expect the cusp to be a little higher in a P. atcoensis tooth of that overall size. Jess 2 Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 19, 2017 Share Posted December 19, 2017 On 12/15/2017 at 8:34 PM, siteseer said: I remember when I met Bruce Welton back in 1994 (he and Roger Farish) was doing signings at shows, promoting the book), I was talking to him about his years collecting in southern California. A collector was behind me and he wanted an ID on an oddball Ptychodus (something like this one showing features of two different species). Bruce kind of sighed and muttered something about Ptychodus not always being easy to Identify to species. With this tooth if pressed for one ID, I would say P. mammilaris because P. atcoensis has such a distnct cusp, appearing to have grown vertically out of the marginal area like a bulb. The tooth in question has a cusp that has a more gradual slope to it from one angle. I would expect the cusp to be a little higher in a P. atcoensis tooth of that overall size. Jess Jess - good observation. I would agree. If truly from Eagle Ford, then P. mammilaris is the best guess. Link to comment Share on other sites More sharing options...
abyssunder Posted December 20, 2017 Share Posted December 20, 2017 As I'm not well versed in this (but curious), it's better to ask, because that's the way how we learn from the more knowledgeable people. Is the tooth in question a lateral file tooth or not? " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 21, 2017 Share Posted December 21, 2017 I am not an expert either - just learning some from Shawn Hamm. That said, my guess is that it is a medial or para-medial file. I think lateral files are not as rectangular, lack symmetry, and the crown is offset from the root. They also can be much harder to identify. Link to comment Share on other sites More sharing options...
JarrodB Posted December 21, 2017 Share Posted December 21, 2017 Roger Farish is the resident tooth expert in our area and a really nice guy. He normally helps me with ID's. Link to comment Share on other sites More sharing options...
sharko69 Posted December 27, 2017 Author Share Posted December 27, 2017 On 12/19/2017 at 4:34 PM, LSCHNELLE said: Jess - good observation. I would agree. If truly from Eagle Ford, then P. mammilaris is the best guess. Received confirmation this evening that the tooth in question is indeed P. atcoensis. Confirmed by Shawn Hamm. 1 Link to comment Share on other sites More sharing options...
LSCHNELLE Posted December 27, 2017 Share Posted December 27, 2017 sharko69: If Shawn is right then, as I said before, you had to be in the Atco Formation of the Austin Group or in the transition. Or, the fossil in question dropped down from the Atco into the Eagle Ford as drift material. 1 Link to comment Share on other sites More sharing options...
sharko69 Posted December 28, 2017 Author Share Posted December 28, 2017 20 hours ago, LSCHNELLE said: sharko69: If Shawn is right then, as I said before, you had to be in the Atco Formation of the Austin Group or in the transition. Or, the fossil in question dropped down from the Atco into the Eagle Ford as drift material. It was found at Post Oak Creek in Sherman. Couldn’t have drifted far to stay in that condition but was float material so that is of coarse possible. Link to comment Share on other sites More sharing options...
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