oilshale Posted January 3, 2011 Share Posted January 3, 2011 (edited) The systematics of Aspidorhynchidae badly needs review. To my knowledge, there are three genera known: Aspidorhynchus, Belonostomus and Vinctifer two of these genera occur in the Upper Jurassic of Solnhofen (Aspidorhynchus and Belonostomus). Vinctifer is common in the Santana Formation of Brazil. The interrelationships of these three genera are more or less unknown. Although the Aspidorhynchidae would have looked superficially similar to the present day gar or a scaled-down version of a modern swordfish, its closest living relative is actually the bowfin. Aspidorhynchus (meaning "shield snout") was a genus of fishes that lived in the Jurassic and Cretaceous period. Aspidorhynchus was a slender, fast swimming fish, with tooth lined, elongated yaws. The upper jaw was longer than the lower jaw, ending in a toothless spike. This is a distinguishing characteristic for Aspidorhynchus and Belonostomus; the upper and lower yaw of Belonostomus having the same length. The largest Aspidorhynchus I have ever seen from Solnhofen would have reached a length of over 1,20 m (4 feet!). Unfortunately, the head was missing. Average size is around 60cm (2 feet). Aspidorhynchus is characterized by a ganoid scale covering with much deepened scales along the flank, by an elongate fusiform body and head with long slender snout, and by an externally symmetrical tail. All fins are rather small. Dorsal and anal fins are positioned far back on the body and opposite one another. The pelvic fins are inserted closer to the anal than to the pectorals. The vertebral column shows some ossification with thin ringlike or half centra. Their slender body profile and the fact that the upper jaw bones were immobile preventing the fish from inhaling their prey, suggest that Aspidorhynchus was designed to be a predator. Fossil stomach remains of other fish have been found in specimens of Aspidorhynchus. Long and delicate gill rakers indicate that this fish was also able to filter feed to supplement its diet. Aspidorhynchus acutirostris Blainville, 1818, the only known species there, is rather common in the Solnhofen Formation (but still much rarer than the Teleostei Leptolepides, Tharsis, Ascalabos and Thrissops). Edited January 3, 2011 by oilshale 1 Be not ashamed of mistakes and thus make them crimes (Confucius, 551 BC - 479 BC). Link to comment Share on other sites More sharing options...
Terry Dactyll Posted January 3, 2011 Share Posted January 3, 2011 oilshale... Ive had a look at both posts... With phenominal examples like those to draw upon for your conclusions you should undertake the review... Brilliant ! Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
Ludwigia Posted January 3, 2011 Share Posted January 3, 2011 Hello Thomas, Thank you very much for these 2 postings! It's clear to see how knowledgeable you are on fish fauna and particularly on the Solnhofen fauna. This is also visible in your wonderful collection. Are you involved by any chance with the Solnhofen Fossilien-Atlas Website? As things are looking they shall soon be joining forces with Steinkern. Best wishes, Roger Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Frank Menser Posted January 3, 2011 Share Posted January 3, 2011 Interesting Be true to the reality you create. Link to comment Share on other sites More sharing options...
oilshale Posted January 4, 2011 Author Share Posted January 4, 2011 Hello Thomas, Are you involved by any chance with the Solnhofen Fossilien-Atlas Website? As things are looking they shall soon be joining forces with Steinkern. Best wishes, Roger Hi Roger, I am a member of these two forums, "Solnhofen Fossilien-Atlas" and "Steinkern". Two great forums with many knowledgeable people and I am glad to hear that they will join forces. But I am not very active there. I prefer TFF. Many nice people here, open discussions and collectors from all over the world. And I can practice some English... Have fun! Thomas Be not ashamed of mistakes and thus make them crimes (Confucius, 551 BC - 479 BC). Link to comment Share on other sites More sharing options...
Plantguy Posted January 13, 2011 Share Posted January 13, 2011 Hi Thomas, fantastic large specimens and a plethora of great detail about them. Thanks for sharing both. I think I have one of the tiny Knightia like guys known as Leptolepides? that you mentioned. Although, I think the label actually says Leptolepis? Is Leptolepsis a valid genus? I'll have to find a photo of the little guy....Regards, Chris Link to comment Share on other sites More sharing options...
oilshale Posted January 17, 2011 Author Share Posted January 17, 2011 Hi Thomas, fantastic large specimens and a plethora of great detail about them. Thanks for sharing both. I think I have one of the tiny Knightia like guys known as Leptolepides? that you mentioned. Although, I think the label actually says Leptolepis? Is Leptolepsis a valid genus? I'll have to find a photo of the little guy....Regards, Chris Hi Chris, ok, Leptolepides will be part 4. Thomas Be not ashamed of mistakes and thus make them crimes (Confucius, 551 BC - 479 BC). Link to comment Share on other sites More sharing options...
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