An dig in the Lower Cretaceous Duck Creek Formation of Texas has yielded three vertebrae that belonged to a mammoth 6.3 - meter - long shark ( that ’s over 20 feet ) . researcher have n’t been able to key out the metal money yet , but whatever it was , it was one of the largest sharks ever documented in the former Cretaceous of North America 100 million year ago , according tofindingspublished inPLoS ONEthis workweek .
The disarticulated vertebra ( OMNH 68860 – see image below ) were name in Albian - long time limestone rock near Fort Worth by members of the Paleontology Club of the University of Wisconsin – Milwaukee in 2009 . The largest one was about 34 millimeters broad and had a diam of 110 millimeters . Fossilized shark vertebrae are fabulously useful for help researchers to estimate full body duration , which then assist clear up the biota and bionomics of prehistorical shark .
To get at a size estimation , a threesome led byJoseph Frederickson from the University of Oklahomacompared the vertebrae to more complete Cretaceous shark fossils – assuming that the human relationship between vertebral sizing and total body length is consistent among shark who live in the open ocean . Additionally , by assuming that the bombastic of the three vertebrae was the largest vertebra of the whole animal , they estimated the small supposed length . This stand for that the shark was 6.3 measure long at lower limit .
equate with shark teeth , however , isolated vertebrae are n’t really very helpful for find out species . This large animal does liken moderately well to a coeval shark ( KUVP 16343 ) that was unearthed from the Kiowa Shale of Kansas . Vertebrae from this specimen had a diam of between 144 and 170 millimeter , and the animal was likely 8.3 to 9.8 meter long . While this shark is bigger , the two may have been of the same species .
unluckily , neither of these specimen were recuperate with associated tooth . But here ’s something interesting : one shark that has been found in both Duck Creek Formation and Kiowa Shale isLeptostyrax macrorhiza , the largest of the vulgar lamniform sharks . ( This radical let in many familiar sharks , such as the peachy white , as well as strange unity like goblin shark . ) In the figure at the top , both KUVP 16343 and OMNH 68860 are reconstruct asLeptostyrax macrorhiza .
As for what they eat , probably " whatever fits in their mouth,“Frederickson enjoin Live Science . This intend large fish as well as marine reptiles like babe pliosaurs , or maybe even fully grown 1 .
mental image : 2015 , Frederickson et al . , PLoS ONE
