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More evidence of swimming dinos reported

April 9, 2013
Courtesy of University of Alberta
and World Science staff

A re­search­er says he has found some of the strongest ev­i­dence that di­no­saurs could pad­dle long dis­tances—an­i­mals per­haps in­clud­ing an an­ces­tral form of the vi­cious Ty­ran­no­saur­us rex.

Work­ing with an in­terna­t­ional re­search team, grad­u­a­te stu­dent Scott Per­sons of the Uni­vers­ity of Al­ber­ta in Can­a­da ex­am­ined un­usu­al claw marks on an old riv­er bot­tom in Chi­na. The chan­nel was known to have been a ma­jor travel-way for di­no­saurs, ac­cord­ing to the re­search group.

Artist's ren­der­ing of a swim­ming thero­pod dino­saur. (Cour­tesy Na­than E. Rog­ers / U. of Al­berta)


Along­side fos­sil­ized foot­prints of many an­i­mals in­clud­ing gi­ant long-necked di­no­saurs, the re­search­ers said they found a se­ries of claw marks that Per­sons said in­di­ca­tes a co­or­di­na­ted, left-right, left-right pro­gres­sion.

They’re “scratch­es left by the tips of a two-legged di­nosaur’s feet,” said Per­sons. “The di­nosaur’s claw marks show it was swim­ming along in this riv­er and just its tip­py toes were touch­ing bot­tom.”

The find­ings da­te to the Cre­ta­ceous pe­ri­od, the lat­er part of the era when di­no­saurs dom­i­nat­ed Earth. A re­port on the work, pub­lished April 8 in the jour­nal Chin­ese Sci­ence Bul­le­tin, comes just a few months af­ter an­oth­er study on swim­ming di­no­saurs. That one at­trib­ut­ed many track marks in a park in Aus­tral­ia to doz­ens of lit­tle plant-eating di­no­saurs, which may have swum or wad­ed with the help of cur­rents.

The marks in­ves­ti­ga­ted in the new study cov­er 15 me­ters or yards and are be­ing at­trib­ut­ed to a meat-eating “theropod” di­no­saur that stood roughly a me­ter at the hip. Theropods were a line­age of di­no­saurs that in­clud­ed T. rex and which mostly ate meat and walked on two legs.

With just claw scratch­es to go with, Per­sons said the ex­act ident­ity of the pad­dling di­no­saur is un­known, but he sus­pects it could have been an early ty­ran­no­saur or Sinocal­liopteryx. Both types of preda­tors were known to have been in that ar­ea of Chi­na.

Fos­sil­ized rip­pling and ev­i­dence of mud cracks indica­te that over 100 mil­lion years ago the riv­er, in the modern-day Szechuan Prov­ince, went through dry and wet cy­cles, the sci­en­tists added. The riv­er bed, which Per­sons de­scribes as a “di­no­saur super-highway,” has yielded plen­ty of full foot prints of oth­er thero­pods and gi­gantic four-leg­ged di­no­saurs called sauro­pods.


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A researcher said he has found some of the strongest evidence that dinosaurs could paddle long distances—animals perhaps including an ancestral form of the vicious Tyrannosaurus rex. Working with an international research team, graduate student Scott Persons of the University of Alberta in Canada examined unusual claw marks on an old river bottom in China. The channel was known to have been a major travel-way for dinosaurs, according to the research group. Alongside easily identified fossilized footprints of many animals including giant long-necked dinosaurs, researchers said they found a series of claw marks that Persons said indicates a coordinated, left-right, left-right progression. They’re “scratches left by the tips of a two-legged dinosaur’s feet,” said Persons. “The dinosaur’s claw marks show it was swimming along in this river and just its tippy toes were touching bottom.” The findings date to the Cretaceous period, the later part of the era when dinosaurs dominated Earth. A report on the work, published April 8 in the journal Chinese Science Bulletin, comes just a few months after another study on swimming dinosaurs. That one attributed many track marks in a park in Australia to dozens of little plant-eating dinosaurs, which may have swum or waded with the help of currents. The marks investigated in the new study cover 15 meters or yards and are being attributed to a meat-eating “theropod” dinosaur that stood roughly a meter at the hip. Theropods were a lineage of dinosaurs that included Tyrannosaurus rex and which mostly ate meat and walked on two legs. With just claw scratches to go with, Persons said the exact identity of the paddling dinosaur is unknown, but he suspects it could have been an early tyrannosaur or Sinocalliopteryx. Both types of predators were known to have been in that area of China. Fossilized rippling and evidence of mud cracks indicate that over 100 million years ago the river, in the modern-day Szechuan Province, went through dry and wet cycles, the scientists added. The river bed, which Persons describes as a “dinosaur super-highway,” has yielded plenty of full foot prints of other theropods and gigantic four-legged dinosaurs called sauropods.