Exquisitely preserved fossils belong to an extinct radical of giant shark have been identify in Mexico , and may help oneself solve some one C - old whodunit surrounding what these enigmas looked like , what they hunt , and how they tally into the shark evolutionary tree .
Ptychodusis a genus of extinctsharksfrom the Albian – Campanian leg of the Cretaceous period ( around 105 to 75 million age ago ) . It contains at least 16 species , which have an estimated gigantic torso size of up to 10 meters ( 33 feet ) and have been find on all Continent except Antarctica .
First reported in 1729 , the genus is still to this day one of the most perplexing fossilelasmobranchs – a group of fish that includes sharks , skate , and ray . heap of weird tooth have been found , but more elaborate fossils , have cranial and post - cranial bony factor , are very rarely discovered and staring specimens had never been reported before now .
Ptychodustooth.Image credit: Vullo et al., Proceedings B, 2024
But that ’s all changed with a new cogitation , in which complete articulated specimens from the early former Cretaceous of Mexico are discover , including a preserved body abstract , which provide essential selective information aboutPtychodusand its mysterious modus vivendi .
“ The new complete skeletons described here help correct the long - standing enigma ofPtychodus , ” the discipline ’s authors write – helping to resolve doubt we ’ve had for almost two century about its anatomy , human relationship to other metal money , and predatory behaviour .
Phylogenetic and ecomorphological depth psychology reassert that , as suspected , Ptychoduswas a titan . The research worker propose a maximal body length of 9.7 meters ( 31.8 feet ) , with a corresponding jaw length of 1.9 meters ( 6.2 foot ) . For reference , the gravid living durophagous shark – shark that corrode severely - shell organisms , such as corals , shell mollusks , or crabs – is just 2.5 to 3.5 meters ( 8.2 to 11.5 foot ) long . Overall , the researcher conclude thatPtychoduswas “ belike the largest durophagous shark that ever be ” .
Fully articulatedPtychodusspecimens from the early Late Cretaceous.Image credit: Vullo et al., Proceedings B, 2024
They also demonstrate that the baffling selachian was a debauched - swimming predator , belong to the mackerel shark group ( Lamniformes ) , an order that also includes thegreat white shark .
Ptychodusalso “ occupied a specialized predatory niche previously unknown in fossil and extant elasmobranch ” , the squad excuse .
The recent find in Mexico “ challenges the widely held sight that [ … ] Ptychoduswas a group of bottom - dwelling sharks flow mainly on shelled benthal invertebrate ” . Instead of snack on organisms likeclamsand crustaceans that populate at the bottom of the ocean , the field authors think thatPtychoduspreferred hard - trounce prey items such asammonitesand ocean turtles .
They also have a theory for what might have brought about its extinction during the Campanian – 10 million years before theCretaceous – Paleogene defunctness eventthat wiped out around three - quarters of Earth ’s specie .
During this prison term , Ptychoduswould have been in unmediated competition with emerging blunt - toothedmosasaursin the clade Globidensini and Prognathodontini . With their crushing teeth , these predators in all probability targeted the same prey asPtychodus , which may have been driven to defunctness as a result .
The study is publish inProceedings of the Royal Society B : Biological Sciences .
