An­cient NZ whale, new dis­cov­ery

Waitaki Herald - - YOUR LOCAL NEWS -

A new species of whale found in a South Is­land quarry is the old­est known ‘‘true’’ baleen whale in the world and its skull is es­ti­mated to have been al­most as long as a per­son is tall.

Toipa­hautea waitaki is es­ti­mated to have lived about 27.5 mil­lion years ago, but a fossil of the whale was re­cov­ered from a work­ing quarry in the Hakataramea Val­ley of South Can­ter­bury in 1988.

How­ever, it was only worked on re­cently. Now, New Zealand and Tai­wanese re­searchers have iden­ti­fied the fossil as a new genus and species of whale.

When the fossil was un­cov­ered, re­searchers found a range of sep­a­rated but as­so­ci­ated bones in­clud­ing a par­tial skull, the lower jaw, ver­te­brae, two scapu­lae, a par­tial humerus and ribs.

From the ex­ist­ing fossil bones the es­ti­mated skull length was 1.5 to 1.6 me­tres long and the body was es­ti­mated to be about 5m long. By whale stan­dards, that was on the small side.

Ex­am­i­na­tion of the fossil sug­gested the spec­i­men was a phys­i­cally im­ma­ture in­di­vid­ual, ei­ther ju­ve­nile or sub-adult age.

The jaw struc­ture was con­sis­tent with baleen-as­sisted gulpfeed­ing, re­searchers said.

Baleen whales are a group of Mys­ticeti, large whales usu­ally from colder wa­ters that lack teeth but have baleen plates in the up­per jaw which are used to fil­ter food such as krill out of large quan­ti­ties of seawa­ter.

A pa­per de­scrib­ing the whale said: ‘‘The ori­gin of baleen and mi­crophagous feed­ing by cetaceans marks a ma­jor evo­lu­tion­ary break­through, lead­ing ul­ti­mately to the emer­gence of the largest an­i­mal, the blue whale.’’

The Univer­sity of Otago’s Pro­fes­sor Ewan Fordyce said the dis­cov­ery was sig­nif­i­cant in New Zealand’s fossil his­tory.

‘‘This is a pretty old whale that goes al­most half-way back to the age of the di­nosaurs. We are track­ing whale his­tory back through time.

‘‘This newly-named whale [is] about as old a com­mon an­ces­tor as we have for the liv­ing baleen whales like the minke whales and the right whales.’’

Fordyce ex­pected the an­cient whales’ his­tory books may keep be­ing rewrit­ten in years to come.

‘‘We are pretty sure there are some species [of baleen whale] that will be older than th­ese. But right now it an­chors the mod­ern baleen whale lin­eage to at least 27.5 mil­lion years.’’

Fordyce and his for­mer stu­dent, Dr Cheng-Hsiu Tsai, named the whale. In Ma¯ori, it means ‘‘a baleen-ori­gin whale from the Waitaki re­gion’’.

The re­searchers were not able to de­ter­mine how the whale died.

Fordyce said it could have been at­tacked by a shark, stranded on a beach or died of dis­ease.

When it died, it sank to the bot­tom of the sea floor with its skele­ton fall­ing apart and be­com­ing a hub for co­ral and other or­gan­isms to grow on.

A pa­per de­scrib­ing the whale was pub­lished on Wed­nes­day in the sci­en­tific jour­nal Royal So­ci­ety Open Sci­ence.

Baleen whales are a group of Mys­ticeti, large whales usu­ally from colder wa­ters that lack teeth. Here’s a cast of a prim­i­tive baleen whale Tokarahia. (FILE PHOTO)

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