Palaeocarcharias Explained

Palaeocarcharias is an extinct genus of shark, known from the Jurassic of Europe. It has only a single named species, Palaeocarcharias stromeri, which is known from exceptionally preserved specimens from the Late Jurassic (Tithonian) of Germany (Solnhofen Limestone) and France (Canjuers Lagerstatte). Isolated teeth of indeterminate species from England (White Limestone Formation, and possibly the Forest Marble and Taynton Limestone) extend the range of the genus back to the Middle Jurassic (Bathonian).^[1] Morphologically, it closely resembles carpet sharks (Orectolobiformes), and is around 1m (03feet) in total body length.^[2] However, it shares greater similarities in tooth development with mackerel sharks (Lamniformes), including the absence of orthodentine, and has been suggested to the earliest known member of the Lamniformes or a member of a sister group to the Lamniformes.^{[3] [4]} A 2018 study suggested that should be classified as the sole member of the order Palaeocarchariiformes, but a subsequent 2023 study questioned this and favoured placement in Lamniformes.

Notes and References

1. Villalobos-Segura . Eduardo . Stumpf . Sebastian . Türtscher . Julia . Jambura . Patrick . Begat . Arnaud . López-Romero . Faviel . Fischer . Jan . Kriwet . Jürgen . 2023-03-08 . A Synoptic Review of the Cartilaginous Fishes (Chondrichthyes: Holocephali, Elasmobranchii) from the Upper Jurassic Konservat-Lagerstätten of Southern Germany: Taxonomy, Diversity, and Faunal Relationships . Diversity . en . 15 . 3 . 386 . 10.3390/d15030386 . 1424-2818 . 7614348 . 36950327 . free .
2. Shimada . Kenshu . Becker . Martin A. . Griffiths . Michael L. . 2021-11-02 . Body, jaw, and dentition lengths of macrophagous lamniform sharks, and body size evolution in Lamniformes with special reference to 'off-the-scale' gigantism of the megatooth shark, Otodus megalodon . Historical Biology . en . 33 . 11 . 2543–2559 . 10.1080/08912963.2020.1812598 . 2021HBio...33.2543S . 224935604 . 0891-2963.
3. Landemaine . Olivier . Thies . Detlev . Waschkewitz . Jens . 2018-11-01 . The Late Jurassic shark Palaeocarcharias (Elasmobranchii, Selachimorpha) – functional morphology of teeth, dermal cephalic lobes and phylogenetic position . Palaeontographica Abteilung A . 312 . 5–6 . en . 103–165 . 10.1127/0375-0442/2018/0000/0085. 2018PalAA.312..103L . 146540287 .
4. Jambura . Patrick L. . Kindlimann . René . López-Romero . Faviel . Marramà . Giuseppe . Pfaff . Cathrin . Stumpf . Sebastian . Türtscher . Julia . Underwood . Charlie J. . Ward . David J. . Kriwet . Jürgen . 2019-07-04 . Micro-computed tomography imaging reveals the development of a unique tooth mineralization pattern in mackerel sharks (Chondrichthyes; Lamniformes) in deep time . Scientific Reports . en . 9 . 1 . 9652 . 10.1038/s41598-019-46081-3 . 31273249 . 6609643 . 2019NatSR...9.9652J . 2045-2322. free .