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In March of this year I found a heteromorphic ammonite that has had me curious ever since. So yesterday I finally sent an email about it to a local ammonite expert, Ron Morin, who is associated with the Dallas Paleontological Society. I had a correspondence with him in May of this year as it related to him identifying my Phlycticrioceras trinodosum heteromorphic ammonite which I recently added to 'Collections'. That's when I first talked to him. Then at the Dallas Paleontological Society's Fossil Mania event in October, I was talking to Roger Farish about my unidentified ammonite. He recommended that I contact him again for identification. Here is the email and the pictures that I sent him yesterday. I will post an update to this thread when he responds, which from my experience might be weeks. I have edited it to remove any slightly sensitive information like my name and more specific location information (I'm paranoid), as well as to fix any grammatical errors and to add relevant reference designations in between the < and > symbols: "Hello! I am Heteromorph, the one who contacted you to identify my Phlycticrioceras trinodosum specimen in May of this year, and I was wondering if you could help me identify another heteromorphic ammonite from the Upper Coniacian stage of the Austin Chalk. This specimen was found on March 23 of this year in a creek in Ellis county. It is, in fact, within half a mile of where I found the last specimen that I sent to you for identification. The stratigraphy of this area is the Atco member of the Austin Chalk, Prionocycloceras gabrielense zone. My problem is that even though it resembles P. trinodosum, there are differences that would make me reluctant to indenify it as such. To date, I have not found one like it. It is similar to P. trinodosum in that the whorl section is compressed, it has ventral tubercles, and it has an open planispiral shape. But it also has 3 key differences that make me think it is either a different species or it is very pathological. I list these below. First and foremost, the main difference is the lack of any ventrolateral tubercles, which are one of the defining characteristics of P. trinodosum. On both the specimen itself and its negative, it appears to be free of any ventrolateral tubercles. The only tubercles that I can see are the ventral tubercles which are something that P. trinodosum has as well. Second, the ribs are shaped differently than P. trinodosum. While P. trinodosum has rectiradiate ribs, this specimen has ribs which are rectiradiate until about half way up from the umbilicus, at which point it bends. Due to the fragmentary nature of this specimen, I have a hard time determining whether it bends abapically or adapically. Third, the ribs are more costate on this specimen than any of the twelve P. trinodosum specimens that I have found in the Austin Chalk. It has a rib index of 7, while the most costate specimen that I have found and know for sure is a P. trinodosum specimen only has a rib index of 5. While this is not unheard of for this species, with specimens of this species having rib indexes of up to 8 (Emerson et al. 1994), yet from my experience it is apparently very unusual for this part of the Austin Chalk. The closest thing that I have seen to my specimen is illustrated on Plate 11, fig 2 of Young, 1963 (as P. sp. cfr. douvillei), the similarity being the fact that they both have rib indexes of 7. After that, though, the similarity ends in that P. sp cfr. P. douvillei still has ventrolateral tubercles and rectiradiate ribs. I also found a very small P. trinodosum negative in the same creek just a few feet away. It has ventrolateral tubercles and a rib index of 4. The ribs are rectiradiate. A photo of it is not attached here. My specimen is 87mm long including its negative and has a whorl height of 34½mm. The oval whorl section is compressed like P. trinodosum. It is shown first in the attached photo DSCN5355. Aside from the specimen in question, for reference I have also attached photos of two P. trinodosum specimens that I have found. They are both from within 5 miles of the creek site, so they are on roughly the same stratigraphic level. What I am calling P1 is shown first in the attached photo DSCN5281 <F13> in comparison with the specimen in question. P1's negative is shown first in the attached photo DSCN5394 <22>. The positive is 69mm long when both pieces of it are measured together but 53mm when just measuring the largest piece. It has a whorl height of 31mm and a whorl breadth of 9mm. Rib index of 4. It was found within a quarter of a mile of the creek site. Because it is has just a slightly shorter whorl section to the specimen in question it is a good comparison piece. The specimen which I am calling P2 is shown in the attached photo DSCN5361 <F27>. It is only a negative but I am attaching a picture of it here because it is the specimen that I referenced earlier with a rib index of 5. It is 23mm long and has a whorl height of 15mm. It was found about 4-5 miles to the south-west of the creek site. For reference, here is a post I made about the P. trinodosum specimen that I sent you a picture of in May. I thank you very much for your help in advance. Sincerely, Heteromorph" I have given an alphanumerical designation to each picture for ease of reference. I guess it is probably kinda silly to have so many pictures that this is necessary. If this is stupid, than I extent my apologies to the Mods. I will patiently receive correction. Thank you to everyone in advance. F1 F2 F3 F4
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Looks like students of UNLV found bones of dinosaur which are now being studied by the Las Vegas Natural History Museum. The bones appear to be that of a hadrosaur and if named would be a first for Nevada News report attached and check out video in that report http://news3lv.com/news/local/new-dinosaur-species-discovered-in-valley-of-fire
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Dear Guys, I recently collected three examples of interesting small bones that have the cavities in the same area, I found them in flint erratics of South Lithuania. One scientist (Jens Koppka) told be that one time the occasional bird bone in flint was found by his colleagues in Lithuania. I recenly found the link with very similar shape of bone known as Enantiophoenix in the middle picture of one publication that I share with you now : https://peerj.com/articles/1032/ Open this link and look for "Comparison of scapulocoracoid between the dromaeosaurid Balaur and other paravians", the cavity in the second scapulocoracoid picture is named as "snf". Please look at my fossil pictures and this link and help with confirmation if you could. Best Regards Domas
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Hello, I came across this piece in a rock/fossil shop during a recent road trip. It was labeled as unidentified dinosaur vertebrae - late Cretaceous 66 million years ago - from the Fort Crittenden Formation in Arizona. I bought it because it's an interestingly shaped piece - any thoughts or ideas? Neck, tail, or back? Thank you for your help.
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From the album: MY FOSSIL Collection - Dpaul7
Inoceramus Bivalves SITE LOCATION: West Point, Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Inoceramus (Greek: translation "strong pot") is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous. The taxonomy of the inoceramids is disputed, with genera such as Platyceramus sometimes classified as subgenus within Inoceramus. Also the number of valid species in this genus is disputed. Inoceramids had a thick shell paved with "prisms" of calcite deposited perpendicular to the surface, which gave it a pearly luster in life. Most species have prominent growth lines which appear as raised semicircles concentric to the growing edge of the shell. Paleontologists suggest that the giant size of some species was an adaptation for life in the murky bottom waters, with a correspondingly large gill area that would have allowed the animal to survive in oxygen-deficient waters. Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: †Praecardioida Family: †Inoceramidae Genus: †Inoceramus -
From the album: MY FOSSIL Collection - Dpaul7
Inoceramus Bivalves SITE LOCATION: West Point, Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Inoceramus (Greek: translation "strong pot") is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous. The taxonomy of the inoceramids is disputed, with genera such as Platyceramus sometimes classified as subgenus within Inoceramus. Also the number of valid species in this genus is disputed. Inoceramids had a thick shell paved with "prisms" of calcite deposited perpendicular to the surface, which gave it a pearly luster in life. Most species have prominent growth lines which appear as raised semicircles concentric to the growing edge of the shell. Paleontologists suggest that the giant size of some species was an adaptation for life in the murky bottom waters, with a correspondingly large gill area that would have allowed the animal to survive in oxygen-deficient waters. Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: †Praecardioida Family: †Inoceramidae Genus: †Inoceramus -
From the album: MY FOSSIL Collection - Dpaul7
Inoceramus Bivalves SITE LOCATION: West Point, Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Inoceramus (Greek: translation "strong pot") is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous. The taxonomy of the inoceramids is disputed, with genera such as Platyceramus sometimes classified as subgenus within Inoceramus. Also the number of valid species in this genus is disputed. Inoceramids had a thick shell paved with "prisms" of calcite deposited perpendicular to the surface, which gave it a pearly luster in life. Most species have prominent growth lines which appear as raised semicircles concentric to the growing edge of the shell. Paleontologists suggest that the giant size of some species was an adaptation for life in the murky bottom waters, with a correspondingly large gill area that would have allowed the animal to survive in oxygen-deficient waters. Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: †Praecardioida Family: †Inoceramidae Genus: †Inoceramus -
From the album: MY FOSSIL Collection - Dpaul7
Inoceramus Bivalves SITE LOCATION: West Point, Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Inoceramus (Greek: translation "strong pot") is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous. The taxonomy of the inoceramids is disputed, with genera such as Platyceramus sometimes classified as subgenus within Inoceramus. Also the number of valid species in this genus is disputed. Inoceramids had a thick shell paved with "prisms" of calcite deposited perpendicular to the surface, which gave it a pearly luster in life. Most species have prominent growth lines which appear as raised semicircles concentric to the growing edge of the shell. Paleontologists suggest that the giant size of some species was an adaptation for life in the murky bottom waters, with a correspondingly large gill area that would have allowed the animal to survive in oxygen-deficient waters. Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: †Praecardioida Family: †Inoceramidae Genus: †Inoceramus -
From the album: MY FOSSIL Collection - Dpaul7
Inoceramus Bivalves SITE LOCATION: West Point, Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Inoceramus (Greek: translation "strong pot") is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous. The taxonomy of the inoceramids is disputed, with genera such as Platyceramus sometimes classified as subgenus within Inoceramus. Also the number of valid species in this genus is disputed. Inoceramids had a thick shell paved with "prisms" of calcite deposited perpendicular to the surface, which gave it a pearly luster in life. Most species have prominent growth lines which appear as raised semicircles concentric to the growing edge of the shell. Paleontologists suggest that the giant size of some species was an adaptation for life in the murky bottom waters, with a correspondingly large gill area that would have allowed the animal to survive in oxygen-deficient waters. Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: †Praecardioida Family: †Inoceramidae Genus: †Inoceramus -
From the album: MY FOSSIL Collection - Dpaul7
Petrified Wood SITE LOCATION: West Point, Cumings, Co., Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Lake Superior Agate - Petrified wood (from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization. All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material. The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place. The organic matter needs to become petrified before it decomposes completely. A forest where such material has petrified becomes known as a petrified forest. Kingdom: Plantae -
From the album: MY FOSSIL Collection - Dpaul7
Petrified Wood SITE LOCATION: West Point, Cumings, Co., Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Lake Superior Agate - Petrified wood (from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization. All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material. The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place. The organic matter needs to become petrified before it decomposes completely. A forest where such material has petrified becomes known as a petrified forest. Kingdom: Plantae -
From the album: MY FOSSIL Collection - Dpaul7
Petrified Wood SITE LOCATION: West Point, Cumings, Co., Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Lake Superior Agate - Petrified wood (from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization. All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material. The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place. The organic matter needs to become petrified before it decomposes completely. A forest where such material has petrified becomes known as a petrified forest. Kingdom: Plantae -
From the album: MY FOSSIL Collection - Dpaul7
Petrified Wood SITE LOCATION: West Point, Cumings, Co., Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Lake Superior Agate - Petrified wood (from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization. All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material. The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place. The organic matter needs to become petrified before it decomposes completely. A forest where such material has petrified becomes known as a petrified forest. Kingdom: Plantae -
From the album: MY FOSSIL Collection - Dpaul7
Petrified Wood SITE LOCATION: West Point, Cumings, Co., Nebraska, USA TIME PERIOD: Late Cretaceous (75-100 Million Years Ago) Data: Lake Superior Agate - Petrified wood (from the Greek root petro meaning "rock" or "stone"; literally "wood turned into stone") is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization. All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the stem tissue. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material. The petrifaction process occurs underground, when wood becomes buried under sediment or volcanic ash and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the covering material deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mold forms in its place. The organic matter needs to become petrified before it decomposes completely. A forest where such material has petrified becomes known as a petrified forest. Kingdom: Plantae -
From the album: MY FOSSIL Collection - Dpaul7
Fossil Mosasaur Teeth Khourigba, Morocco TIME PERIOD: Late Cretaceous (~70 Million Years ago) Data: First and most importantly, mosasaurs are not dinosaurs. Mosasaurs (from Latin Mosa meaning the 'Meuse river', and Greek sauros meaning 'lizard') are an extinct group of large marine reptiles. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. During the last 20 million years of the Cretaceous period (Turonian-Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago. Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Family: †Mosasauridae -
This heteromorphic species is characterized by an open plain spiral shape with slightly rursiradiate ribs and 3 sets of tubercles; 2 sets of ventrolateral tubercles, and 1 set of ventral tubercles. The whorl section is compressed and does not have constrictions in United States specimens but does have constrictions in many European specimens. The distance between ribs is roughly the same as the width of a rib. As far as I know, there are only two species reported for this genus, with the other being Phlycticrioceras rude from the late Santonian of France (Kennedy 1995). P. trinodosum is the only species reported in Texas. This species shows two morphotypes, with the more commonly found robust from having a lower rib index and the less commonly found gracile form having a higher rib index. This dimorphism is likely sexual, with the robust form being female and the gracile form being male. This particular specimen is a robust form with a rib index of roughly 3 1/2, but some gracile specimens of this species exhibit a rib index of up to 8 (Emerson 1994). The highest rib index of a P. trinodosum specimen that I have found is 7, this being on a fragment of a very mature gracile specimen. That specimen (seen here) shows very weak ventrolateral tubercles, a trait shared with all the other gracile specimens that I have seen thus far. This is in contrast to the strong ventrolateral tubercles of the robust form. It was broken in two when it separated from the rock shown in the last photo, with its outer whorl being shown in the 4th and 5th photos. The outer whorl is 53mm long, and at the top where the whorl height is measurable, it is 16mm. You can see in the photos of the main part of the specimen, the impression of where its outer whorl once was. The complete specimen would be about 65-70mm in diameter if its outer whorl was still connected. When applicable and needed, I have put the relevant pages for information, plates, and text figures at the end of references: Ulrich Kaplan und William James Kennedy (1994). Ammoniten des westfälischen Coniac. Geologie und Paläontologie in Westfalen, Heft 31, 155 S. Pages 53, 54; Tafel 37, Figures 2-4, 9-15 on pages 142, 143; Tafel 43, Figure 3 on pages 154, 155. Zdenek Vašíček (1990). Coniacian ammonites from Štíty in Moravia (Czechoslovakia). Sbornik geologickych ved, Paleontologie 32, Pages 163-195. Pages 177, 179; Plate VI with its explanation is on page 193. Young, K. (1963). Upper Cretaceous Ammonites from the Gulf Coast of the United States. University of Texas, Publication 6304, 373 pp. Pages 45, iv, 39, 47, 371; P. sp. cfr. douvillei on pages 45, iv, 23, 26, 29, 371; Plate 4, figures 2, 3 on pages 150, 151; Plate 11, figure 2 on pages 168, 169; text figure 7 f, h on pages 156, 157. W. J. Kennedy (1984). Systematic Paleontology and Stratigraphic Distribution of the Ammonite Faunas of the French Coniacian. Palaeontological Association, London, Special Papers in Palaeontology, No. 31. Pages 136, 137; Plate 32, figures 4, 11 on pages 140, 141; text figure 42E on pages 146, 147. David L. Clark (1963). The Heteromorph Phlycticrioceras in the Texas Cretaceous. Journal of Paleontology, Vol. 37, No. 2, pp. 429-432. W. J. Kennedy, M. Bilotte and P. Melchior (1995). Ammonite faunas, biostratigraphy and sequence stratigraphy of the Coniacian-Santonian of the Corbieres (NE Pyrenees). Additional links to information concerning this paper can be found here and with the species Phlycticrioceras rude, listed here. Kennedy, W.J. and Cobban (1991). Coniacian Ammonite Faunas from the United States Western Interior. Palaeontological Association, London, Special Papers in Palaeontology, No. 45, 96pp. Barbra L. Emerson, John H. Emerson, Rosemary E. Akers and Thomas J. Akers (1994). Texas Cretaceous Ammonites and Nautiloids. Paleontology Section, Houston Gem and Mineral Society, Texas Paleontology Series Publication No. 5, 438 pp. Pages 285, 286, 388, 422. Ulrich Andrew S. Gale, William James Kennedy, Jackie A. Lees, Maria Rose Petrizzo and Ireneusz Walaszczyk (2007). An integrated study (inoceramid bivalves, ammonites, calcareous nannofossils, planktonic foraminifera, stable carbon isotopes) of the Ten Mile Creek section, Lancaster, Dallas County, north Texas, a candidate Global boundary Stratotype Section and Point for the base of the Santonian Stage. Acta Geologica Polonica, Vol. 57, No. 2, pp. 113-160. The 1st, 2nd, 4th and 8th papers also contain information on Tridenticeras, another heteromorphic genus found in the Austin Chalk alongside P. trinodosum. A big thanks to DPS Ammonite. This is my first post to 'Collections' and he helped me get it all straight.
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I found this clam eroding from a concretion in the Carlile Shale (Turonian) outcrops which I hike regularly. After much debate (with myself ) about the i.d. of this clam, I want to label it as panopea sp. (the modern species is referred to as a geoduck) but wanted to post it here to get your thoughts as well. Is this a fossil geoduck? Thanks for pondering, -P.
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went hunting in a small site that normally produces small crow shark teeth and enchodus teeth and pieces of turtle shell and found this bone. not sure what it belonged to.thanks
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Late Cretaceous small tetrapods found in Lithuania
D.N.FossilmanLithuania posted a topic in Fossil ID
Dear Guys, I made the pictures of possible big discovery in Late Cretaceous erratics of Lithuania. There are some frog bones in flints (ilium, urostyle, tibiofibula, scapula), snake pieces (tibiofibula like of Tetrapodophis! and one thin scale), and toothed birs upper and lower jaw fossils. If you could confirm these finds, it will be the first further my article in scientific magazine and I wish it will be successful. There will be some posts, please review the pictures and tell what do you think. At first, I will show you frog remains. Best Regards Domas The second part- snake remains.
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A couple of years ago, while on a romp through the Rio Puerco Valley, I found this ammonite. Since then, I have attempted to find a proper i.d. for this specimen through literature and documentation of New Mexico's Late Cretaceous ammonites. With very little luck, the closest resemblance were ammonites in the subfamily Puzosiinae, which are not documented from New Mexico. Today I decided to show the curator and the ammonite researcher at the New Mexico Museum of Natural History and Science. Good news...they did not know what it was! ...pretty exciting. Anyhoo, I have donated it to be studied but figured I would post it here as well. Unknown ammonite from the Late Cretaceous (Cenomanian) Paguate Mbr. of the Dakota Formation - New Mexico, USA. I doubt they'll be jumping on this right after lunch, but I will let ya'll know the results as I do. Happy hunting, -P.
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Chiropractor discovers BC's first dino skull. Looks like a Tyrannosaurid. Pretty good find while on holiday http://www.cbc.ca/amp/1.4158748
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I literally joined the forum 5 minutes ago, and I am still learning about the technicalities of paleontology. So if I use terms or vocabulary in the wrong context please excuse me. I have recently acquired a bone fragment that was found in the Hell Creek Formation near Jordan Montana,and it is from the Late cretaceous period. This is all I currently know about this fossil. I need help identifying the species that this bone fragment is from. Thanks for the help !
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Zuul crurivastator David Evans of the ROM contributed in describing a new ankylosaur from northern Montana's Judith River Fornatikn. One of the most complete Ankylosaurs ever found ROM's release http://www.rom.on.ca/en/collections-research/research-community-projects/zuul http://blogs.discovermagazine.com/deadthings/2017/05/09/meet-zuul-crurivastator-i-aint-fraid-of-no-ankylosaur/#.WRJrc5BlDxA http://www.sciencemag.org/news/2017/05/demon-faced-dinosaur-named-after-ghostbusters-baddie
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Stratigraphy of the Late Cretaceous North America
Troodon posted a topic in General Fossil Discussion
Placement of terrestrial formations in the late cretaceous of North America as been constantly evolving and in October 2016 Denver Fowler a Paleontologist at the Museum of the Rockies published a very extensive paper on the subject and updated most units. This is very important when it comes to understanding dinosaur evolution and aids in describing species. This paper is in the process of going through peer review so is subject to change. Fowler DW. (2016) A new correlation of the Cretaceous formations of the Western Interior of the United States, I: Santonian-Maastrichtian formations and dinosaur biostratigraphy. PeerJ Preprints 4:e2554v1https://doi.org/10.7287/peerj.preprints.2554v1 The paper is pretty technical but all of the data is found in this excel file (supplemental information) which is a massive high-resolution stratigraphic chart for all of the formations from the late cretaceous of North America. It's nice to see it all laid out and a great reference source. https://doi.org/10.7287/peerj.preprints.2554v1/supp-1 To make it easy I've broken the chart apart so you can easily see most important dinosaur formations Texas The biggest change came with our understanding the Aguja and Javelina Formations of Texas part of the Tornillo group. The study indicated that the Aguja Formation deposits are only Campanian in age and that the Javelina Formation does not extend into the end of the Cretaceous. Very important when trying to describe species in those formations. Sellers have been comparing the Aguja to the Judith River in Montana well there is a correlation but its deposits are much younger that JR. Eastern Montana, N. Dakota, S. Dakota and Wyoming What I found interesting is that the Hell Creek is much older in Montana than in the adjacent states. The other interesting observation that can been easily be seen on these charts is that the how short a time frame the deposits of the Hell Creek/Lance formation are compared to the other major dinosaur formations. Central Montana Two Medicine and Judith River Formations are the two key formations in this locality Utah and New Mexico Utah depicted on the left and NM on the right Head North to Canada Alberta and Saskatchewan
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