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Showing results for tags 'chondrichthyes'.
Found 26 results
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I know very little about shark teeth. I found this one a while back in Pennsylvanian (Desmoinesian) shale in northeastern Oklahoma. I am speculating this may be deltodus only because I see a nearly identical tooth labeled as deltodus on another website. The fossil is very thin (too thin to photograph the edges). Besides confirming the taxonomy, can anyone tell me which surface of the tooth is shown in Side A? Finally, would you say Side B is mainly matrix (other than the edges)? I think matrix is showing through the cracks on Side A, and that may be the only thing holding the fossil together. My wife recently got me a camera, so I am working on a gallery album in the forum. I would like to make sure I have the IDs correct before I post photos in the album, so you may be seeing several ID requests from me over the next weeks. Best wishes
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- elasmobranch
- desmoinesian
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From the album Chondrichthians
The more flattened version and 3 extra fragments from another Petalodus -
From the album Chondrichthians
A few Petalodus teeth fragments I have found -
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From the album Muncie Creek Shale Nodules
Currently being donated and Identified. Will update on this specimen if this is a new species and its identification. -
From the album Muncie Creek Shale Nodules
Currently being donated and Identified. Will update on this specimen if this is a new species and its identification. -
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From the album Muncie Creek Shale Nodules
The second half of the cartilage pterygiophores When breaking the concretion most of the internal structure was unfortunately damaged -
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From the album Muncie Creek Shale Nodules
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Help request! I am putting together a tool for judging rock age based on very crude, whole-rock, hand-sample observations of fossil faunas/floras -- the types of observations a child or beginner could successfully make. I view this as a complement to the very fine, species-level identifications commonly employed as index fossils for individual stages, biozones, etc. Attached is what I've got so far, but I can clearly use help with corals, mollusks, plants, vertebrates, ichnofossils, and the post-Paleozoic In the attached file, vibrant orange indicates times in earth history to commonly observe the item of interest; paler orange indicates times in earth history to less commonly observe the item of interest. White indicates very little to no practical probability of observing the item of interest. Please keep in mind that the listed indicators are things like “conspicuous horn corals,” purposefully declining to address rare encounters with groups of low preservation potential, low recognizability, etc. Got additions/amendments, especially for the groups mentioned above? Toss them in the comments below! Thank you..... https://docs.google.com/spreadsheets/d/1tVm_u6v573V4NACrdebb_1OsBEAz60dS1m4pCTckgyA- 5 replies
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- pelecypoda
- gastropoda
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A new publication explores the transition between C. chubtensis and C. megalodon, loss of cusplets Please note the following statement about lineage by some very influential authors: "we do not feel that the transition from angustidens to chubutensis is as marked as suggested by Cappetta (2012), given that the lineage represents a chronospecies with very gradual morphological change through time. As such, we choose to maintain a single genus for all serrated forms, given that they are easily distinguished from Otodus obliquus, and use the genus Carcharocles for subsequent taxa (C. auriculatus through C. megalodon) because the description of Carcharocles by Jordan and Hannibal (1923) precedes that of Megaselachus by Glickman (1964)." Journal of Vert Paleontology https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1546732 The transition between Carcharocles chubutensis and Carcharocles megalodon (Otodontidae, Chondrichthyes): lateral cusplet loss through time Victor J. Perez , Stephen J. Godfrey, Bretton W. Kent, Robert E. Weems & John R. Nance @siteseer
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- carcharocles megalodon
- chondrichthyes
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Hello, I am looking for help identifying a specimen collected during field work for my dissertation. The piece was collected from the Lower Oxford Clay (jason zone) in Peterborough, Cambs. I suspect that it is Ischyodus egertoni, but am not positive whatsoever! Any thoughts would be appreciated Cheers, Jacob.
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- chondrichthyes
- vertebrae
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Red Hill is a site I first went to 10 years ago with my son, Ian who was 10 at the time. It is a very deep road cut into the uppermost part of the Catskill Formation representing a late Fammenian river system that was draining the Acadian mountains to the east and emptying into the inland sea in western PA and OH. It is one of a handful of sites in the world where Devonian tetrapods have been found. The site has fossil layers in both channel margin (red layers) and flood plain (gray-green layers) facies. While it is an active research site and groups go there under the understanding that anything of scientific importance will be donated to the museum, there is a lot there that is redundant in the collections and we've been able to retain. In 2014, Ian found an exceptionally preserved moderately large osteolepiform, Hyneria (Tristichopteridae). Some of the material went into the re-description of Hyneria, much we have been allowed to take home. Since then the project has expanded to a search for more tetrapod material using the jackhammer and generator the museum purchased. This may require multiple posts. I'll start with the jaws recovered over 2014/15 seasons. This lens containing most of the head from apparently a single individual. Here Ian is working with Ted Daeschler and Doug Rowe (site manager) of the Academy Of Natural Sciences in Philadelphia. Here are some images of the jaw material after removal and after prep by Fred Mullison of the ANSP. Lower left jaw after removal. This is the lower right jaw (right) and the vomer and very impressive fang. Amazingly, in 2016, we went back. I was leading a trip for DVPS. Ian found this amazing but poorly prepped jaw (I did this one). Here are a pair of cleithrums, about 29 cm long. The attachments for the scapulocoracoid are clearly visible between 17 and 21 cm. Here is part of the parietal shield. More to follow.
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- tetrapoda
- chondrichthyes
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Johnson/2003Mitt.Mus.NaturkBerl., Geowiss. Reihe 6 (2003) 125-160 Nature of the beast (pun intended): taxonomical (systematic) Monograph " Dentitions of Barbclabomia (new genus, Chondrichthyes: Xenacanthiformes) from the Upper Palaeozoic of North America Gary D. Johnson' With 14 figures and 3 tables recommended, particularly for those interested in xenacanthids, orthacanthids, etc About 5 Mb Abstract Barbclabornia luedersensis (Berman, 1970) is defined on the basis of small (2 111117 high) isolated teeth that lack an intermediate cusp. It is known from the Lower Permian and possibly the Upper Pennsylvanian of North America. The two principal cusps are slightly curved orally, nearly parallel, and bear cristae mainly on their distal halves. They are cylindrical but become compressed proximally. The long axis of each cusp base is >45" to the labial margin of the tooth base. The base bears a prominent apical button in contact with the cusps; a central foramen is absent. Fewer than ten foramina occur on the aboral surface of the base, which bears a prominent concave basal tubercle. The shape of the base ranges from somewhat triangular to quadrangular. The cusps are composed of orthodentine covered by hypermineralized pallial dentine; the base is composed of orthodentine but may also contain trabecular dentine. Except for the possible occurrence of symphysial teeth, the dentition is homodont. Barbclabornia cf. B. luedersensis is stratigraphically highest in the known range of the genus and is restricted to the nearly lowermost part of the Clear Fork Group (Artinskian) of Texas. The teeth are similar to B. lztedersensis, but are more robust and have a quadrangular-shaped base. Barbclabornia was large, based on an undescribed palatoquadrate some 45 cm long. It was probably freshwater and is most closely related to Triodus. Key words: Chondrichthyans, Xenacanthiformes, Early Permian, North America.
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- morphometry
- usa
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Giuseppe Marramà, Kerin M. Claeson, Giorgio Carnevale & Jürgen Kriwet(about 4 Mb) (2018) Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat- Lagerstätte, Italy, reveals the first fossil embryo insitu in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes, Journal of Systematic Palaeontology, 16:14, 1189-1219, DOI: 10.1080/14772019.2017.1371257 Sensitive people should beware of figs. 15 and 16 I resisted the temptation (lover of classic photography) to work Man Ray in there somewhere
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- vertebrates
- ontogeny
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awesom 11,3 Mb I just received a postcard from my retinae:"enjoying the Bahamas,won't be back anytime soon,you &*&(((()_+&@W" "And you may tell yourself :"This is not my beautiful fossil""
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I can't identificate it. I found it at marine sandstone from Paleogene. Also, do somebody has a handbook about chondrichthyes of Cappetta 2012 in PDF?
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EHRET_al-2012-Palaeontology.pdf
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- elasmobranch
- pisces
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After this horrendous attempt at a triple pun,things can only deteriorate,right? The list of species in the tags i have kept to a bare bones minimum,for clarity's sake i MIGHT not have posted this,but it figures tooth rows. Shark cognoscendi prolly already have this one(and the others by Bass)I'm sure. SO,no need to post those others orrep38a.pdf
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Over the last two years I have been able to collect a small but diverse group of shark and other chondrichthyan teeth from Pennsylvanian deposits in Illinois. Actually, all but one of the teeth are from one exposure of the La Salle Limestone of the Bond Formation- the other tooth was found in some roadside rip rap limestone in Central Illinois which seems to share many species with the La Salle, but unfortunately I have no way of determining the exact origin. Here is the first tooth, this is the one collected from rip rap in northern Champaign County. It is a cladodont type tooth, although unfortunately most of the main tooth and some of the cusps are missing. The tooth is 15 mm across at the widest point.
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- chondrichthyes
- shark
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big the name says it all: it IS big
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- biology
- neontology
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Just guessing this hasn't been posted yet.... Enjoy,well illustrated account shark
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Taphonomy of a fascinating oddball........... Itano-piscselach2015-AbradedEdestus-final.pdf
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This might help a bit in answering questions about shark vertebrae:springerselachpiscevertebraosteologymetricsUSNMP-116_3496_1964.pdf
