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Found 38 results

  1. Silly Season

    It’s that time of year... Ancient Marine Fossils Unearthed in Plano, nbcdfw.com
  2. I am right now out in the field, attempting to extract a string of articulated reptile vertebrae in the lower Atco. It is in a soft marl bed just a few feet above the basal Atco. There seems to be articulated ribs associated with the specimen, and so far I have uncovered 14 verts. 9 of them were lose of the surface and bagged in ziplocks, but now I am trying to get the rest out. If anyone has any advice, I need it! The specimen also has articulated ribs. I want to get this thing home tonight, and not destroyed. This is is my first time attempting to extract vertebrae, and I want to do it right and get it home tonight. It is currently 8:54 p.m. here in North Texas. Here are some pictures of the bones when I found them and where the dig is now. I don’t know what exactly it is, but I am guessing juvenile Mosasaur. Age is Earliest Coniacian. 9 verts were on the surface, and at least 6 more uncovered with ribs. Pictures incoming: All 9 verts. @Uncle Siphuncle @erose
  3. I found this Phlycticrioceras trinodosum heteromorph specimen in June of 2018 whilst hunting the middle/upper Coniacian Atco formation. It is the largest fragment of this species that I am aware of, having a whorl height of 51 mm as opposed to 47 mm of the largest fragment I've seen published. This genus is a bigger, rarer, and (mostly) younger cousin of Allocrioceras. I sent pictures of it to Keith Minor and he pointed out that there was also an echinoid sticking out of the specimen, something which I had totally missed! With much of the echinoid still stuck in the living chamber it is hard to get a definitive ID. But because it has such a shallow anterior ambulacra, which gives the anterior end a more smooth rather than definitive heart shape, he ruled out both Mecaster texanus and batensis. He suggested Micraster since the site has a strong European component in both the bivalve and ammonite faunas, and because the periproct side has the right shape. From finding other, although not as well preserved specimens that show similar morphology he appears to be right. I have yet to confirm this ID with Andrew Smith, but either way I think the piece is worth showing. And reading this thread got me thinking about how this could have happened and what effect it could have had on the echinoid's preservation. My thought is that because irregular echinoids lived and today still live most of their lives burrowing in the sediment it is unlikely that it would have crawled into the living chamber, but instead that it was blown into it post-mortem via currents that had dredged it out of the sediment. I already know that this site was a high energy environment from my other finds here so this seems the most likely possibility to me. But because of the fact there is still at least one spine still attached to the specimen it could not have been swept up from the sediment too long after death or all of its hairlike spines would have blown away. I do, however, find it interesting that it is positioned anterior first with its posterior towards the aperture, the position I would expect to see it in if it had indeed crawled into the shell. The specimen is also the best preserved echinoid from this site so far. Despite the ammonites being generally well preserved and not too crushed, most of the echinoids that I have from the site are terribly crushed, flakey, and often infested with rotting pyrite. I think being encapsulated in the chamber very much reduced those effects. Even though the ammonite and the echinoid are a bit crushed, the echinoid would have probably been worse off otherwise. The heteromorph fragment length is 70 mm and the whorl breadth, being a bit crushed, is 13 mm. I would think that this specimen, with its open planispiral coiling, would would have been at least over a foot in diameter when complete. It is the robust (female) morph of the species with a rib index of 5½. For comparison in Fig. 1 I pictured it with my most complete P. trinodosum specimen. From the part of the echinoid that is exposed I can measure 25 mm in length, 25 in width, and a thickness of 8 mm. I have also found abundant yet scattered fish remains at the site, so perhaps one day an ammonite-fish will come my way. But until then, anyone else got ammonite-echinoids to show? Fig. 1. Fig. 2.
  4. Scapanorhynchus

    I want to tap into all of the expertise that is on this site again! I am doing research on a faunal assemblage of the Coniacian age from north central New Mexico. It is quite a large grouping, with over 12,000 teeth from over 25 species. I am currently working on scapanorhynchus, and am looking for some guidance. Some of the teeth have labial plications, and Cicimurri et. al. argues that this is most likely due to ontogenetic reasons. However, this paper is the only one I can find that even mentions labial plications on Western Interior Seaway scapanorhynchids. Do you have any thoughts about this? Any and all help will be greatly appreciated!
  5. Psuedocorax

    Hey all, I am once again coming to you, as this board has some incredible people on it with a vast wealth of knowledge. I have a question about the genus Pseudocorax. Do they have serrations, or don't they? Welton and Farrish write that the crowns of P. granti are smooth..."cutting edges smooth and very thin." Yet I see photos on the net of P. affinis that definitely have serrations. Does ones specie of Pseudocorax have serrations while another doesn't? Thank you in advance for any information relating to this! Randy
  6. Asking for more squalicorax help

    I have done some more research on the squalicorax that I posted about a few weeks ago. I ended up examining 886 teeth or fragments thereof. Of these, 79 showed a fossilization process in which the serrations (and sometimes the whole cusp) was covered with a white mineral. 48 were so worn that sometimes the serrations could barely be made out. 254 were too small or fragmented to be of any use (which does not preclude that they were of the same species as the rest). The remaining 632 all had the ornamentation that is so unusual. They can be found only on the labial side of the cusp (forgive my previous posts saying that they were on the lingual side...a stupid mistake on my part), and the majority are on the mesial edge of the cusp, although a smaller percentage have the ornamentationon the distal edge, and even fewer have them on both. . There are three types of ornamentation, the least common being a horizontal band below the top of the cusp. The second type consists of a small circular indentation, and can be found anywhere on the serration. The most common is a vertical triangle, with the apex of the triangle towards the top of the serration. I have no clue as to whether this is due to ontological heterodonty, sexual dimorphism, placement within the jaw, or something else. If anybody could check their S. falcatus examples (the closest that these teeth resemble), or any other Coniacian squalicorax, and see if this ornamentation is found beyond the fauna I am working on. I have corresponded with Mike Everhart (Oceans of Kansas), and this is new to him. All help will be greatly appreciated! I will post two pictures here, then two more immediately after. Thanks again! Randy
  7. Squalicorax

    Hey everyone, I don't have a lot of comparative material at hand, so I am asking for your help. I am working on a large shark fauna from the Cabezon area of New Mexico. The teeth are very beat up, possibly due to wave action on offshore sand bars. However, upon close inspection of the better teeth I have discovered that the serrations on the lingual side of the teeth contain indentations (or possible enable folding...see the photo). I have some squalicorax teeth from the Turonian, about 25 miles from this site, that were described in the New Mexico Museum of Natural History and Science Bulletin 52 (Bourdon, et. al., I was the tail end author) that also have these features. The closest we could identify these teeth were to slap a cf. or an aff. on them. Those of you who have identified to species squalicorax, could you check and see if they also have these lingual indentations or folds? Are these normal on all squalicorax species? Thank you!!! Randy Pence
  8. At a site where I have been finding heteromorphs, I have recently come across some vertebrate material. So far I have only found three vertebrate specimens; one bone fragment and two fish scales. I am hoping to get some information on their affinities. I am most interested in the fish scales, since it seems they would be the most easily identified. The site is in North Texas, the Austin Chalk group, Atco formation, upper Coniacian stage. For biostratigraphic reference, at this same site I have also found the ammonites Protexanites planatus, Phlycticrioceras trinodosum, Tridenticeras peramplum, Scaphites semicostatus, and Glyptoxoceras sp., among others. The bone (Figs 1-17) was found on Saturday the 14th of July. It is a small fragment from a more marly layer than the fish scales and most of the rare ammonites that I am finding are from, but still from the same site. The main part of it has 39 mm exposed length wise as shown in Figs 11-12 (some of it is still buried in the rock), and has a branch coming from the main part that is 22 mm long that forms a depressed canal structure in the rock (Fig. 14). The maximum thickness of the specimen that I can see is about 2 ½ mm. The branch begins to curve around when it meets the main part of the bone. The other end of the rock and the underside don't show much exposure of the bone except for a few bits poking through (Figs 16-17). I don’t know if the specimen came from a fish or some other vertebrate, but I would guess fish. If anyone can give more information on what kind of animal this came from and where this might have been located in the animal’s skeleton, that would be much appreciated. But I also know that due to its very fragmentary nature, a more definite identification may not be possible. The two fish scales (Figs 18-20) were both found on Friday the 27th of July over 100 yards from where the bone was found. These specimens are from a more chalky matrix than the bone, the same matrix that the rare ammonites are in. The first specimen (Figs 18-19) was found breaking open a large chunk of chalk. It is basically flawless and in excellent condition, and only has a little bit of obscuring matrix on the right side that could be prepped off. In the same chunk of rock that I cracked open to find this I also found a T. peramplum specimen. The fish scale is 5 ½ mm long by 5 ½ mm wide. The second fish scale I found (Fig. 20) was found within a few feet of the first one, possibly from the same fish specimen. It is a bit beat up and less complete than the first scale, but is larger from what I can see. It is 7 mm wide including the flatended area upon which the scale once was before it flaked away during excavation. The front part of it is still buried in the rock but could hopefully be prepped out. It is also in a chalky chunk of rock, not marly. I have noticed that these are less shiny than scales preserved in shales, though they still do glimmer a bit in direct light. They are also differently colored than most fish scales preserved in shales, with mine being on the red/brown spectrum while those in shale are usually black or dark gray. I am hoping that the distinctive symmetrical 7 way splitting shown on the first fish scale could narrow down the identification. I know that getting to the species or genus level could be very difficult, but could a family or order be at least possible? I have heard that identifying fish scales is challenging, but this paper indicates that it is not impossible. @oilshale, you’re a fishy guy (in a good way of course). Any ideas? Fig. 1.
  9. Coniacian Glyptoxoceras?

    Is anyone aware of any Glyptoxoceras sp. in the Coniacian? @doushantuo, I know that you are good at digging up information like this. Can you find anything?
  10. During april i and a friend had the oportunity to spend a few days hunting in cretaceous of Normandy, hunting for echinoids. Day one : We drove from brittany through Le Havre to Saint Jouin de Bruneval and Antifer Cape. (3 hours and a half) We let the car on the beach parking lot and hiked south on the peeble shore looking for fossils in the boulders on the beach. The cliff is cenomanian with a bit of albian at the bottom. You have to look carefully on rocks surface for the familliar spherical shape. I found about 20 urchins but thats about it. No shark tooth, just a poorly preserved ammonite (mantelliceras) and a few rhynchonellas At some point we noticed tide was coming back faster than expected, most likely because of the wind pushing the water back. We had to quicken the pace, and made our way through the slippery covered with algae rocks. We finally managed our way back to the car and took the road to Fécamp where we had booked an hotel for the next 2 nights. some finds of the day : Crassiholaster subglobosus : Crassiholaster subglobosus : Cyclothyris difformis : See the all hunt gallery here http://www.thefossilforum.com/index.php?/gallery/album/2849-haute-normandie-april-2018/ or on my flickr : https://flic.kr/s/aHsmiwWft6
  11. Micraster decipiens - 6

    From the album Haute normandie - April 2018

    Micraster decipiens : a cretaceous echinoid from Saint-Pierre en Port
  12. Micraster decipiens - 5

    From the album Haute normandie - April 2018

    Micraster decipiens : a cretaceous echinoid from Saint-Pierre en Port
  13. Micraster decipiens - 4

    From the album Haute normandie - April 2018

    Micraster decipiens : a cretaceous echinoid from Senneville sur Fécamp
  14. Micraster decipiens - 3

    From the album Haute normandie - April 2018

    Micraster decipiens : a cretaceous echinoid from Senneville sur Fécamp
  15. Micraster decipiens - 2

    From the album Haute normandie - April 2018

    Micraster decipiens : a cretaceous echinoid from Senneville sur Fécamp
  16. Kingena elegans group

    From the album Haute normandie - April 2018

    Kingena elegans : a cretaceous brachiopod from Senneville sur Fécamp
  17. Kingena elegans

    From the album Haute normandie - April 2018

    Kingena elegans : a cretaceous brachiopod from Senneville sur Fécamp
  18. Echinoids : best from the april 2018 hunt

    From the album Haute normandie - April 2018

    Last hunt from Normandy cretaceous : best of echinoids
  19. From the album Haute normandie - April 2018

    Last hunt in cretaceous from Normandy : the whole loot
  20. Echinocorys gravesii - 2

    From the album Haute normandie - April 2018

    Echinocorys gravesii : an echinoid from Normandy cretaceous.
  21. Echinocorys gravesii - 1 -2

    From the album Haute normandie - April 2018

    Echinocorys gravesii : an echinoid from Normandy cretaceous.
  22. Echinocorys gravesii - 1 - 1

    From the album Haute normandie - April 2018

    Echinocorys gravesii : an echinoid from Normandy cretaceous.
  23. Indet shark tooth

    From the album Haute normandie - April 2018

    Indet shark tooth from Normandy cretaceous.
  24. Does anyone have a ballpark figure for the amount of time it takes one species to evolve into or diversify into another? I am working on a shark fauna that comes from the Coniacian, and one of the genera is only known from one species that was found in the Santonian (Scindocorax novimexicanus). This site is one to two million years older, and the species is definitely a part of the Scindocorax genus. This is only the second occurrence of this anocoracid reported from New Mexico, and although the teeth compare with that described from the Santonian, I'm wondering if the age difference would indicate a separate species. The Scindocorax novimexicanus photo is a lingual view of a left anterior tooth, while the Scindocorax sp. photo is a labial view of a left lateral tooth. Thanks!
  25. I have been doing more research on my unidentified Middle/Upper Coniacian heteromorph ammonite that I posted pictures and information on here, and with lots of papers and information from Keith Minor I think that I have narrowed it down to two ammonite genera, Neocrioceras and Pseudoxybeloceras. He sent lots of very helpful papers including Kennedy and Cobban's 1991 paper Coniacian ammonite faunas from the United States Western Interior. It includes pictures and information on 3 species of Neocrioceras and one species of Pseudoxybeloceras from the Coniacian Western Interior. Keith also emailed me some information that I will show here. At first I thought that my specimen could be Smedaliceras durhami which is so far known only from the Campanian Burditt Formation of south Texas. That was way out there and Keith didn't even consider that possibility because of how out there that suggestion was. Then I saw pictures on the internet of an Allocrioceras hazzardi specimen from Utah that did look similar to mine. The main problem with that theory is that A. hazzardi doesn't have lateral tubercles, so scratch that. It was after exchanging emails with Keith that I came to my aforementioned conclusion, that my specimen is either of the genera Neocrioceras or Pseudoxybeloceras. After studying Kennedy and Cobban 1991 a bit further it seems to me that Neocrioceras (Schlueterella) sp. most closely resembles my specimen. N. sp. has one set of lateral and ventral tubercles on both sides of the specimen respectively. The tubercles connect groups of 2-3 ribs. Between the tuberculate groups there are up to 6 finer non-tuberculate ribs. At first I said that on my specimen there were 7 non-tuberculate ribs between the tuberculate ones but on closer examination the tuberculate ribs come in groups like N. sp. with one tubercle connecting two ribs. In reality my specimen has 6 non-tuberculate ribs between each tuberculate group consisting of two ribs. The main difference that I notice is that my specimen has much weaker lateral tubercles than N. sp. Interestingly, Neocrioceras is not known from the Austin Chalk but there are a couple Pseudoxybeloceras specimens reported from the Santonian stage of the Austin Chalk in central Texas. The main reason why I don't think my specimen is Pseudoxybeloceras is because the species P. dispar, the only species of this genus reported from the Coniacian Western Interior in Kennedy and Cobban 1991, is quadrituberculate on every rib with no ribs being non-tuberculate. But I will say that I have not seen nor read any detailed descriptions of the Pseudoxybeloceras species found in the Austin Chalk so I still consider it a very possible candidate, though my specimen is considerably older. @Wrangellian, I know that you have experience with this genus from the Santonian. What do you think? In this post I also include 3 pictures of 2 different inoceramid specimens I found along with my heteromorph specimen. I sent Keith these pictures to help pin point my heteromorph's stratigraphic position in the Coniacian. Anyone have any ideas on what species they are? From what I am hearing from Keith my ammonite specimen could be a bit older than the Prionocycloceras gabrielense zone if these inoceramids are in the Magadiceramus subquadratus group. I will update this thread when I receive more information. Here are the edited relevant emails from my exchange with Keith: ______________________________ Keith Minor, February 17. Hi Heteromorph, According to Kennedy et al., Phlycticrioceras douvillei and P. oregonensis are junior synonyms of P. trinodosum. P. trinodosum has been found in several areas around the Cretaceous Tethys Sea. According to Walaszczyk, The Trinodosum Zone is middle Coniacian, which is consistent with the level that you are finding your specimens. Cremnoceramus ranges up into the middle Coniacian. However, I think that the clams that you have are probably Magadiceramus, probably M. subquadratus group. So the heteromorphs are slightly lower than the Prionocycloceras gabrielense's that you are finding, and your Texanitine could actually be Protexanites shoshonense, which would be about the right level. Also, I didn't put two and two together, but that big piece of a heteromorph that you showed me may actually be Neocrioceras, which doesn't have tubercles, or Pseudoxybeloceras, with small tubercles that fade on the body chamber. I hope this helps! Keith ______________________________ Heteromorph, February 22. Here are two websites with the pictures of the alleged Allocrioceras hazzardi specimen that I found pictures of online. The more I look at the pictures the less I think that the specimen is really A. hazzardi. I have never seen another A. hazzardi specimen that looks like it and all the descriptions that I have read on the species don't indicate this kind of variation. I now believe that it was misidentified, but I wonder what you think. http://www.ammonoid.com/coniacian.htm https://www.tonmo.com/threads/heteromorphs.11130/page-4#post-156740 So, do you have an opinion as to what species my specimen is? For me I am having trouble deciding between Pseudoxybeloceras (Pseudoxybeloceras) dispar or Neocrioceras sp. What I do know is that the alleged A. hazzardi specimen from Utah very much resembles mine. Thank you for all your help! ______________________________ Keith Minor, February 22. Hi Heteromorph, I see the images. Yes, that is definitely Allocrioceras hazzardi. It ranges from the Upper Turonian (Prionocyclus hyatti Zone) to the Upper Coniacian (Prionocycloceras gabrielense Zone). I don't know of any Santonian species. Hazzardi is probably the descendant of Allocrioceras annulatum from the Upper Cenomanian. Kennedy also described A. conlini, but I'm not sure that this is a separate species. I attached (as a Google Drive link) Kennedy's review of Eagle Ford ammonites (Texas). You can see that the ribs are all the same size in annulatum, but in hazzardi, the the spine-bearing ribs are bigger, and also hazzardi is a larger species. I double checked to see if Hamites and Anisoceras ranges up into the Coniacian, but they disappear in the Cenomanian (as far as I can tell), so these genera can be ruled out. However, Neocrioceras and Pseudoxybeloceras are genera that need to be considered. I have some papers on these, I think from South Africa. I'll find those when I have time. There's a couple of Pseudoxybeloceras specimens from the Austin Chalk from central Texas (Santonian). Kind regards, Keith Late Cenomanian and Turonian Ammonite faunas from north-east and central Texas ______________________________ P1 - Inoceramid oyster P2 - Same inoceramid oyster showing more clearly the perpendicular ribbing.
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