Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


Strange marine mammals of ancient North Pacific revealed

The pre-Ice Age marine mammal community of the North Pacific formed a strangely eclectic scene, research by a Geology PhD student at New Zealand’s University of Otago reveals.

Studying hundreds of fossil bones and teeth he excavated from the San Francisco Bay Area’s Purisima Formation, Robert Boessenecker has put together a record of 21 marine mammal species including dwarf baleen whales, odd double-tusked walruses, porpoises with severe underbites and a dolphin closely related to the now-extinct Chinese river dolphin.

Among his finds, which were fossilized 5 to 2.5 million years ago, is a new species of fossil whale, dubbedBalaenoptera bertae, a close relative of minke, fin, and blue whales.

Mr Boessenecker named the whale in honour of San Diego State University’s Professor Annalisa Berta, who has made numerous contributions to the study of fossil marine mammals and mentored many students.

Although an extinct species, it belongs within the same genus as minke and fin whales, indicating that theBalaenoptera lineage has lasted for 3-4 million years. Balaenoptera bertae would have been approximately 5-6 meters in length, slightly smaller than modern minke whales, Mr Boessenecker says.

His findings appear in the most recent edition of the international journal Geodiversitas.

The publication represents eight years of research by Mr Boessenecker, who was 18 in 2004 when he was tipped off by a local surfer about bones near Half Moon Bay. When he discovered the fossil site, he was astonished by the numerous bone-beds and hundreds of bones sticking out of the cliffs.

He excavated the incomplete skull of Balaenoptera bertae during early field research there in 2005 and it wasencased in a hard concretion that took five years to remove.

“The mix of marine mammals I ended up uncovering was almost completely different to that found in the North Pacific today, and to anywhere else at that time,” he says.

Primitive porpoises and baleen whales were living side-by-side with comparatively modern marine mammals such as the Northern fur seal and right whales. And species far geographically and climatically removed from their modern relatives also featured, such as beluga-like whales and tusked walruses, which today live in the Arctic, he says.

“At the same time as this eclectic mix of ancient and modern-type marine mammals was living together, the marine mammal fauna in the North Atlantic and Southern Ocean were already in the forms we find today.”

Mr Boessenecker says this strange fauna existed up until as recently as one or two million years ago. Its weirdness was likely maintained by warm equatorial waters and barriers to migration by other marine mammals posed by the newly formed Isthmus of Panama, and the still-closed Bering Strait.

“Once the Bering Strait opened and the equatorial Pacific cooled during the Ice Age, modernised marine mammals were able to migrate from other ocean basins into the North Pacific, leading to the mix we see today,” he says.

Mr Boessenecker was supported by University of Otago Doctoral Scholarship and a Montana State University Undergraduate Scholars Research Grant during this research.


Click for big version.

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

China Shopping: NZ-China FTA Upgrade Agreed Among Slew Of New Deals

New Zealand Prime Minister Bill English and China Premier Li Keqiang signed off a series of cooperation deals spanning trade, customs, travel and climate change and confirmed commencement of official talks on an upgrade to the nine-year old free-trade agreement between the two countries. More>>

ALSO:


Media: TVNZ Flags Job Cuts To Arrest Profit Decline

Chief executive Kevin Kenrick said the changes were aimed at creating "a sustainable future video content business for TVNZ in an ever-changing media market." More>>

ALSO:

Reserve Bank: Wheeler Keeps OCR At 1.75%

Reserve Bank governor Graeme Wheeler kept the official cash rate unchanged at 1.75 percent, as expected, and reiterated his view that the benchmark rate doesn't need shifting for the foreseeable future. More>>

ALSO:

Trade Plans: Prime Minister's Speech To International Business Forum

"The work to improve public services, build infrastructure, and solve social problems is possible only because we have enjoyed sustained, solid economic growth. A big reason for that is the Government’s consistent agenda of economic reform, and our determination to open up more opportunities for trade with the world." More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news