Largest Leptostyrax macrorhiza

[Sélacien34]

Hello everyone, does anybody knows what is the maximal size of the teeth from Leptostyrax macrorhiza?

I have few informations about this specie and I also would like to know if Leptostyrax macrorhiza is registered from Kazakhstan or if it's a sp.

[fossilselachian]

In "The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas", Welton and Farish list the maximum size of this species as 49mm. My largest example from Texas is 35 mm. I have no information regarding the species from Kazakhstan.

[Sélacien34]

In "The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas", Welton and Farish list the maximum size of this species as 49mm. My largest example from Texas is 35 mm. I have no information regarding the species from Kazakhstan.

My largest is 38 mm but I didn't knew the maximum size, thank you very much for your answer. Nobody saw a largest one than 49 mm ?

We can see that everywhere > http://www.livescience.com/51072-giant-cretaceous-shark-uncovered.html

but it seems that these vertebrae are probably from a Cardabiodontidae shark and not from Leptostyrax macrorhiza as explained M. S. in a post, if I have well understood.

Do we know an estimation about the maximum size of this shark ?

Does someone knows if this specie is known from Kazakhstan ? About the occurrence of Leptostyrax macrorhiza at the strict sense, is it only from America ?

Edited October 18, 2015 by Sélacien34

[fossilselachian]

Leptostyrax macrorhiza is also known from Ken-Kem (Albian) beds of Morocco.Cappetta also reported several European locations for this species. These locations were reported in Cappetta's 1987 "Handbook of Paleoichthyology". I don't know if any new/different information was reported in the subsequent revision of this document.

[Foshunter]

The largest I have found is 38 mm as well found in the Eagle Ford Formation Lake Texoma, Texas. From my experience Complete teeth are more to the rare side, with like mine, long cusps have tendency to seperate from the tooth, is this what others have found as well?

Tom

[Troodon]

The specimen I have from Kazakhstan is labeled the same but very small at 1cm.

Edit: The largest I have from Texas 42mm

Edited October 16, 2015 by Troodon

[Sélacien34]

I have unfortunately not enough good publications about this. In this publication : MODIFICATION DU STATUT GÉNÉRIQUE DE QUELQUES ESPÈCES DE SÉLACIENS CRÉTACÉS ET TERTIAIRES" dating from 1980 Cappetta said :

European species typically attributed to the species macrorhiza COPE under different generic names by the way, are in fact very different from the latter and can be divided into two groups: one consisting of species confined to the Cretaceous and that the you can store in the genre Plicatolamna HERMAN CAPPETTA and CASE in 1975; another limited to the species Protolamna sokolovi November gen. November sp. encountered in the Lower Cretaceous of southern France, England and Japan, and in the Cenomanian of northern France; USSR, its stratigraphic distribution, which would reach the top of the Turonian, needs to be clarified.

Any recent information about this specie stricto sensu, maximum body size estimation, world ditribution etc.., are welcome.

Edited October 16, 2015 by Sélacien34

[Sélacien34]

Leptostyrax macrorhiza is also known from Ken-Kem (Albian) beds of Morocco.Cappetta also reported several European locations for this species. These locations were reported in Cappetta's 1987 "Handbook of Paleoichthyology". I don't know if any new/different information was reported in the subsequent revision of this document.

Could you inform me about all the European locations registered by Cappetta ?

The largest I have found is 38 mm as well found in the Eagle Ford Formation Lake Texoma, Texas. From my experience Complete teeth are more to the rare side, with like mine, long cusps have tendency to seperate from the tooth, is this what others have found as well?

Tom

003.JPG

Thank you for the picture, You've found a nice one-handed too. I have bought my largest one on a famous E.shop, it's from the Paw Paw Formation of the Washita Group, Motorola Site, Tarrant Co. (Albian - late Cretaceous - 112 million years ago). It shows separated cusplets in front of the main cusp, narrow cusp with strong labial ridges at the crown foot, no nutrient groove, large lingual root protuberance as discribed by Cappetta, the perfect holotype.

Edited October 16, 2015 by Sélacien34

[Sélacien34]

The specimen I have from Kazakhstan is labeled the same but very small at 1cm.

Edit: The largest I have from Texas 42mm

Hello, from Kazakhstan, but labeled by who ?

[Troodon]

I believe the ID came from Vladimir Kozlov. There are references to this species in his book "Elasmobranchii and Palaeogene Biostratigraphy of Trans Urals and Central Asia" but it's in Russian and primarily a Palaeogene book.

[fossilselachian]

Here is the example I have as referenced in post #3 above. Size = 36mm.

[Sélacien34]

Very nice tooth too, thanks for the picture. All other/new informations about this specie are welcome.

Edited October 17, 2015 by Sélacien34

[Sélacien34]

Leptostyrax macrorhiza is also known from Ken-Kem (Albian) beds of Morocco.Cappetta also reported several European locations for this species. These locations were reported in Cappetta's 1987 "Handbook of Paleoichthyology". I don't know if any new/different information was reported in the subsequent revision of this document.

I found data about genus Leptostyrax, Kriwet and Al 2008, I already have these informations and that's the best that I have for the moment about these species. It seems that Leptostyrax macrorhiza specie stricto sensu is restricted to the Albian of the USA.

http://www.researchgate.net/publication/235584111_A_new_lamniform_shark_Eoptolamna_eccentrolopha_gen._et_sp._nov._%28Chondrichthyes_Lamniformes%29_from_the_Lower_Cretaceous_of_Iberia

Leptostyrax is a lamniform shark that is generally assigned to the Cretoxyrhinidae, although its tooth morphologies strongly differ from those of Cretoxyrhina. This genus is best known from the Albian–Cenomanian of the USA (Welton & Farish, 1993; Cappetta & Case, 1999), but it also occurs in the ?lower Campanian of Germany (Albers & Weiler,1964), ?Santonian of Sweden (Siverson, 1992), Albian–Cenomanian of England (Underwood & Mitchell, 1999), Albian of Australia (Siverson, 1997), and Albian of Angola (Antunes & Cappetta, 2002).

So far, no associated dentition of this shark has been recovered. However, Welton & Farish (1993) presented a tentative dental reconstruction of Leptostyrax macrorhiza, a species seemingly restricted to the Albian of the USA (Cappetta & Case, 1999) that shows a pair of parasymphyseals and an intermediate upper tooth. In the reconstruction of Welton & Farish (1993), all teeth bear a single pair of lateral cusplets. However, Cappetta & Case (1999) and others indicate that the lateral teeth of L. macrorhiza often bear two pairs of lateral cusplets, indicating some degree of gradient monognathic heterodonty.../

Eoptolamna eccentrolopha gen. et sp. nov. (Chondrichthyes, Lamniformes) from the near coastal upper Barremian Artoles Formation (Early Cretaceous) of Castellote (northwestern Spain) is described on the basis of about 50 isolated teeth. This taxon represents one of the earliest lamniform sharks known to date. We hypothesize that most pre-Aptian lamniforms belong to an ancient group characterized, amongst others, by a very weak gradient monognathic heterodont dental pattern, and by tearing-type dentition. There is a nutritive groove in the lingual root protuberance in juveniles of Eoptolamna, which persists in adults. A single pair of symphysial and a pair of upper intermediate teeth might have been present. Consequently, a new family, Eoptolamnidae, is introduced to include the new form, as well as Protolamna and probably Leptostyrax. The Eoptolamnidae represent an ancient family within Lamniformes. The origin of lamniform sharks remains, however, ambiguous despite recent advances. The new Spanish taxon is widespread in the Barremian of north-eastern Spain, and occurs in a wide range of facies from near-coastal to lake deposits. This lamniform also occurs in the Lower Cretaceous of northern Africa.

Edited October 27, 2015 by Sélacien34

[siteseer]

Selacien34,

Jean-Pierre Biddle collected Leptostyrax from an Albian site called "Presqu' Ile de Nemours, Saint-Dizier region, northeastern France." I have seen only a couple of small specimens of that.

Leptostyrax compressidens has been reported from the Lower Cenomanian of Lussant, France.

Like you, I have a 38mm specimen of Leptostyrax from the Motorola site in Tarrant County, Texas. I was told it was a temporary locality in the early 1990's now filled-in and landscaped-over. Fossilselachian and I know another collector who has a good collection from there and likely has at least one Leptostyrax exceeding 40mm. In my experience most of the largest ones I've seen have come from there.

I'm not sure if Leptostyrax is known from Kazakhstan. If so, it might most likely be from an Albian site called Kolbay. I might have a paper on that but haven't found it after doing some looking.

I think Leptostyrax is more commonly found in the Albian than in the Cenomanian.

Jess

I found data about genus Leptostyrax, Kriwet and Al 2008, I already have these informations and that's the best that I have for the moment about these species. It seems that Leptostyrax macrorhiza specie stricto sensu is restricted to the Albian of the USA.

http://www.researchgate.net/publication/235584111_A_new_lamniform_shark_Eoptolamna_eccentrolopha_gen._et_sp._nov._%28Chondrichthyes_Lamniformes%29_from_the_Lower_Cretaceous_of_Iberia

Leptostyrax is a lamniform shark that is generally assigned to the Cretoxyrhinidae, although its tooth morphologies strongly differ from those of Cretoxyrhina. This genus is best known from the Albian–Cenomanian of the USA (Welton & Farish, 1993; Cappetta & Case, 1999), but it also occurs in the ?lower Campanian of Germany (Albers & Weiler,1964), ?Santonian of Sweden (Siverson, 1992), Albian–Cenomanian of England (Underwood & Mitchell, 1999), Albian of Australia (Siverson, 1997), and Albian of Angola (Antunes & Cappetta, 2002).
So far, no associated dentition of this shark has been recovered. However, Welton & Farish (1993) presented a tentative dental reconstruction of Leptostyrax macrorhiza, a species seemingly restricted to the Albian of the USA (Cappetta & Case, 1999) that shows a pair of parasymphyseals and an intermediate upper tooth. In the reconstruction of Welton & Farish (1993), all teeth bear a single pair of lateral cusplets. However, Cappetta & Case (1999) and others indicate that the lateral teeth of L. macrorhiza often bear two pairs of lateral cusplets, indicating some degree of gradient monognathic heterodonty.../

Eoptolamna eccentrolopha gen. et sp. nov. (Chondrichthyes, Lamniformes) from the near coastal upper Barremian Artoles Formation (Early Cretaceous) of Castellote (northwestern Spain) is described on the basis of about 50 isolated teeth. This taxon represents one of the earliest lamniform sharks known to date. We hypothesize that most pre-Aptian lamniforms belong to an ancient group characterized, amongst others, by a very weak gradient monognathic heterodont dental pattern, and by tearing-type dentition. There is a nutritive groove in the lingual root protuberance in juveniles of Eoptolamna, which persists in adults. A single pair of symphysial and a pair of upper intermediate teeth might have been present. Consequently, a new family, Eoptolamnidae, is introduced to include the new form, as well as Protolamna and probably Leptostyrax. The Eoptolamnidae represent an ancient family within Lamniformes. The origin of lamniform sharks remains, however, ambiguous despite recent advances. The new Spanish taxon is widespread in the Barremian of north-eastern Spain, and occurs in a wide range of facies from near-coastal to lake deposits. This lamniform also occurs in the Lower Cretaceous of northern Africa.

[Sélacien34]

Hello Siteseer,

I'm not sure either that Leptostyrax is known from Kazakhstan, I can only rely on the solid work done by leading experts that I can obtain, and I probably lack of elements, so I make "excavations" here and everywhere on the net, trying to learn more.

So yes, I think it's possible to say that Leptostyrax genus is subcosmopolite, more commonly found in Albian period, registered in America, Europe, Africa, Australia, and Leptostyrax macrorhiza specie seems to be limited from the Albian of America, corresponding to the West interior sea, Texas/Kansas.

I found this work about the Tataouine Basin in southern Tunisia (2013), it shows teeth that look to Leptostyrax, like those found in Kazakstan or in Russia, but the teeth are smaller than L. macrorhiza, as Ward discribed the teeth found in the London Clay of UK, they differ from the specimens found in the Albian of Texas figured by H. Cappetta (1987) and Welton and Farish (1993) in having their lateral cusps more closely applied to the principal cusp, being less lateraly compressed and in having a lightly striated lingual crown.

http://homepage2.nifty.com/megalodon/a4protolamna4.html

http://www.ammonit.ru/tag/1337.htm

In the Tataouine region, macro and microvertebrate remains are recovered from three distinct stratigraphic intervals: the lower Douiret Formation (Barremian), the Chenini (rare) and Oum ed Diab members of the Aïn El Guettar Formation (Albian). The Douiret Formation is characterized by mainly siliciclastic deposits in coastal environments (foreshore to coastal sabkha facies): fossils recovered from this interval are essentially representative of freshwater taxa.

http://amsdottorato.unibo.it/5240/1/Contessi_Michela_tesi.pdf

This kind of teeth seem to be easily confused with other species like Protolamna, and I think about Williamson and Al in their work Selachians from the Greenhorn Cyclothem (“Middle” Cretaceous: Cenomanian – Turonian), Black Mesa, Arizona, and the paleogeographic distribution of Late Cretaceous selachians (1993), which described teeth that look closely to Leptostyrax in the configuration of the root and crown morphology. However, the roots of the specimens available are slightly abraded, and it is therefore difficult to the original extent of the enameloid over the base of the crown on the labial side of each tooth. Moreover, the morphology of these specimens also resembles the smaller species of Cretodus, especially C. borodini (Cappetta and Case, 1975). Also there is a possibility that these teeth may represent the symphyseal teeth of Cretodus semiplicatus, which is present at the same locality.

When you move away from the American type specie things get complicated.

Selacien34,

Jean-Pierre Biddle collected Leptostyrax from an Albian site called "Presqu' Ile de Nemours, Saint-Dizier region, northeastern France." I have seen only a couple of small specimens of that.

Leptostyrax compressidens has been reported from the Lower Cenomanian of Lussant, France.

Like you, I have a 38mm specimen of Leptostyrax from the Motorola site in Tarrant County, Texas. I was told it was a temporary locality in the early 1990's now filled-in and landscaped-over. Fossilselachian and I know another collector who has a good collection from there and likely has at least one Leptostyrax exceeding 40mm. In my experience most of the largest ones I've seen have come from there.

I'm not sure if Leptostyrax is known from Kazakhstan. If so, it might most likely be from an Albian site called Kolbay. I might have a paper on that but haven't found it after doing some looking.

I think Leptostyrax is more commonly found in the Albian than in the Cenomanian.

Jess

Edited October 28, 2015 by Sélacien34

[MikaelS]

The largest Leptostyrax I have is from the Motorola site (Pawpaw) and measures 46 mm in height (not slant height). The cusp is a bit worn so I estimate it was probably 48mm high originally (or about 49mm in slant height). David Ward and I collected there back in 1997 or 1998 (guided by Bruce Welton). David found the tooth which I promptly 'confiscated'. We found a total of 10 Leptostyrax that afternoon.

Edited November 19, 2015 by MikaelS

[Sélacien34]

The largest Leptostyrax I have is from the Motorola site (Pawpaw) and measures 46 mm in height (not slant height). The cusp is a bit worn so I estimate it was probably 48mm high originally (or about 49mm in slant height). David Ward and I collected there back in 1997 or 1998 (guided by Bruce Welton). David found the tooth which I promptly 'confiscated'. We found a total of 10 Leptostyrax that afternoon.

Thank you very much for these informations , the best I can find anyway .

[Dav]

Bonsoir,

Votre discussion est intéressante. Je collecte des dents de l'Albien de France (Bassin anglo-parisien) depuis quelques années maintenant. Contrairement à ce que j'ai pu penser dans le passé et à ce qu'a publié J-P Biddle (1993), l'espèce Leptostyrax Macrorhiza telle qu'est décrite en Amérique semble ne pas exister. Les dents sont sensiblement différentes notamment par la taille beaucoup plus modeste. Cappetta les attribue à Pseudoscapanorhyncus compressidens HERMAN 1977.

David

(Good evening,

Your argument is interesting. I collect teeth from the Albian of France (Anglo-Paris Basin) for some years now. Contrary to what I have thought in the past and what Biddle published JP (1993), the Leptostyrax macrorhiza species such as is described in America seems not to exist. The teeth are significantly different in particular by the much smaller. Cappetta attributes them to Pseudoscapanorhyncus compressidens HERMAN 1977.)

[JP.]

Sorry to hang on the topic so late.

 

In my 1993 paper I wasn't confident about the specific unity of Leptostyrax macrorhiza, so I managed to get some specimens from the Motorola site in Texas afterward.

Indeed the teeth I figured aren't L. macrorhiza, and belong to two other generas, including Pseudoscapanorhynchus.

 

Meanwhile, I have collected one single tooth from the Presqu'Ile de Nemours location that can undoubtedly be attributed to L. macrorhiza. This is only one specimen.

 Typical material originates from the Texan horizons, yes.

 

JP

[Macrophyseter]

On 10/16/2015 at 11:50 AM, Sélacien34 said:

We can see that everywhere > http://www.livescience.com/51072-giant-cretaceous-shark-uncovered.html

but it seems that these vertebrae are probably from a Cardabiodontidae shark and not from Leptostyrax macrorhiza as explained M. S. in a post, if I have well understood.

One thing that bothers me is that every time a loose theory-study is published, the science news go crazy like its official, probably not even saying that its a loose theory subject to complete change.

[Kane]

10 minutes ago, Macrophyseter said:

One thing that bothers me is that every time a loose theory-study is published, the science news go crazy like its official, probably not even saying that its a loose theory subject to complete change.

Sadly, that is par for the course in any regular media reporting on science. As these stories are written for the general public, much of the technical language is stripped, and the study is presented as though it were entirely conclusive without taking into consideration the conditional nature of empirical testing - or the very foundation of the empirical method itself. Usually the scientists who are asked to comment on the story can be taken out of context, with the reporter/writer using a pull quote to package the story for mass consumption. Most often, journalists aim to tell a compelling story which then attracts readership, and thus sales and ad revenue. Between the need to sell a story and presenting an accurate and objective account, the latter rarely wins in such a struggle. 

[Dav]

Bonjour,

Merci pour ta réponse JP.

Pour moi, pas facile de s'y retrouver dans ces dents de requin. Je ne suis pas assez spécialiste.

Et dommage que je n'ai pas de Leptostyrax du Texas à titre de comparaison, je n'ai jamais réussi à m'en procurer.

Quand part-on faire un voyage d'étude aux USA? :-)

Amicalement, David