Dracopristis

Dracopristis (meaning 'dragon shark') is an extinct genus of ctenacanth (a group of shark-like cartilaginous fish) that lived during the Carboniferous period in North America, around 307 million years ago.

Its large spines were likely used for defense against larger fish, while Dracopristis itself was likely a benthic predator that inhabited shallow, brackish-water environments.

[1][5] The specific locality which produced the specimen, the Kinney Brick Quarry, is considered a Konservat-Lagerstätten due to the exceptional quality of its fossils.

[5] The dorsal spines, facial denticles, and rows of teeth have been suggested to give the animal a "dragon-like" appearance,[2][3][5] and -pristis is a common suffix given to shark-like fishes.

[2][5][8][note 1] The specific name, hoffmanorum, is in honor of Ralph and Jeanette Hoffman who own the Kinney Brick Quarry and helped conduct research on the taxon.

[1][13] The "Godzilla" nickname was inspired by the genus' defining exaggerated back spines and teeth, which are said to resemble the famous movie monster of the same name.

[1] D. hoffmanorum had an elongated and dorsoventrally (from top to bottom) flattened body, which is also indicated by the shape of preserved soft tissue impressions and the arrangement of articulated patches of dermal denticles.

Fenestrae which housed cranial nerves are preserved, but the interior of the skull is too severely crushed for its internal nervous anatomy to be studied, even with the use of CT scans.

As in living sharks, the rear portions of the palatoquadrates (upper jaws) articulated with the otic processes (equivalent to ear canals).

[1][4] Their appearance is similar to those of other ctenacanthiforms such as Glikmanius and Heslerodus in sharing a cladodont (multi-cusped) crown morphology and a reniform (d-shaped) root.

[5] Thrinacoselache Doliodus Cladoselache Squatinactis Triodus Orthacanthus Dracopristis Ctenacanthus Homalodontus Hopleacanthus Wodnika Tristychius Surcaudalus Bandringa Sphenacanthus Gansuselache Onychoselache Hamiltonicthys Dracopristis was part of the chondrichthyan order Ctenacathiformes,[5] which were likely part of the subclass Elasmobranchii and were thus relatives of living sharks and rays.

[17] Compared with selachimorph sharks, the ctenacanths had greatly enlarged ornamented fin spines, proportionally large mouths, and akinetic jaw suspension.

[2][5] During the Carboniferous, the Atrasado Formation consisted of estuarine and lagoonal habitats,[1] evidenced by fish specimens which show adaptations to both freshwater and marine environments.

[2][21] The quarry has also yielded numerous specimens of the filter feeding acanthodian Acanthodes, symmoriiforms similar to Cobelodus,[1] hybodonts, holocephalans, ray-finned palaeonisciformes, lungfish, coelacanths, and megalichthyoforms.

[1][21] Rarer genera, such as the large eugeneodont (whorl-tooth shark) Campyloprion and the aforementioned Glikmanius, might have only occasionally migrated into the estuary from deeper, marine habitats.

An exposure of limestone belonging to the Atrasado Formation , photographed along a roadcut near Jemez Springs , New Mexico
The teeth and disarticulated skull of Glikmanius careforum , a potential close relative of Dracopristis
Large, ornamented dorsal spines of ctenacanths , such as Ctenacanthus (pictured) and Dracopristis, are a defining feature of the group
The articulated remains of a large symmoriiform similar to Cobelodus , discovered at the Kinney Brick Quarry [ 1 ]