Hair may have helped mice out­live the di­nosaurs

CityPress - - News -

The T-Rex di­nosaur (pic­tured) may have been the most fe­ro­cious crea­ture in the jun­gle, but some­thing as sim­ple as growing hair may have helped mam­mal-like rep­tiles to out­live this scary beast.

This con­clu­sion fol­lows ground­break­ing re­search by Univer­sity of the Wit­wa­ter­srand sci­en­tists, who are shed­ding light on the an­ces­try of mam­mals and the ori­gin of hair.

Dr Julien Benoit and his col­leagues, pro­fes­sors Paul Manger and Bruce Ru­bidge, scanned the fos­sil re­mains of mam­mal-like rep­tiles from the Ka­roo. They found that well be­fore the Me­so­zoic age, the rep­tiles called ther­a­p­sids may have evolved hair and the use of whiskers as a sen­sory tool to op­er­ate at night.

“Whiskers are an amaz­ing sen­sory tool to have when you are noc­tur­nal, and the evo­lu­tion of whiskers pos­si­bly as­sisted in the sur­vival of the ther­a­p­sids – and more specif­i­cally the probain­og­nathi­ans – which even­tu­ally evolved into mam­mals as we know them to­day,” said Benoit.

Based on anatom­i­cal ob­ser­va­tions in probain­og­nathi­ans, it ap­pears that the MSX2 gene un­der­went a sig­nif­i­cant change in its ex­pres­sion 240 mil­lion to 246 mil­lion years ago and trig­gered the evo­lu­tion of many typ­i­cal mam­malian traits, in­clud­ing hair and whiskers, an en­larged cere­bel­lum, com­plete os­si­fi­ca­tion of the skull roof and, more im­por­tantly, the mam­mary glands that de­fine mam­mals to­day.

– Staff re­porter

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