Featured Research

from universities, journals, and other organizations

Remarkable fossil cave shows how ancient marsupials grew

Date:
July 18, 2010
Source:
University of New South Wales
Summary:
The discovery of a remarkable 15-million-year-old Australian fossil limestone cave packed with even older animal bones has revealed almost the entire life cycle of a large prehistoric marsupial, from suckling young in the pouch still cutting their milk teeth to elderly adults.

Skull of sheep-sized diprotodontid Nimbadon lavarackorum from the middle Miocene cave deposit, AL90.
Credit: Karen Black, UNSW

The discovery of a remarkable 15-million-year-old Australian fossil limestone cave packed with even older animal bones has revealed almost the entire life cycle of a large prehistoric marsupial, from suckling young in the pouch still cutting their milk teeth to elderly adults.

In an unprecedented find, a team of University of New South Wales [Sydney Australia] researchers in has unearthed from the cave floor hundreds of beautifully preserved fossils of the extinct browsing wombat-like marsupial Nimbadon lavarackorum, along with the remains of galloping kangaroos, primitive bandicoots, a fox-sized thylacine and forest bats.

By comparing the skulls of 26 different Nimbadon individuals that died in the cave at varying stages of life the team has been able to show that its babies developed in much the same way as marsupials today, probably being born after only a month's gestation and crawling to the mother's pouch to complete their early development.

Details of the find at a site known as AL90 in the famous Riversleigh World Heritage fossil field in Queensland are published in the Journal of Vertebrate Paleontology, by a team led by Dr Karen Black, of the UNSW School of Biological, Earth and Environmental Sciences. The research was supported by the Xstrata Community Partnership Program North Queensland and the Australian Research Council.

"This is a fantastic and incredibly rare site," says Dr Black. "The exceptional preservation of the fossils has allowed us to piece together the growth and development of Nimbadon from baby to adult. So far 26 skulls -- ranging in age from suckling pouch young and juveniles right through to elderly adults -- have been recovered, as well as associated skeletons.

"The animals appear to have plunged to their deaths through a vertical cave entrance that may have been obscured by vegetation and acted as a natural pit-fall trap. These animals -- including mothers with pouch young -- either unwittingly fell to their deaths or survived the fall only to be entombed and unable to escape.

"The ceiling and walls of the cave were eroded away millions of years ago, but the floor of the cave remains at ground level. We have literally only scratched its surface, with thousands more bones evident at deeper levels in the deposit.'

The site is also scientifically important because it documents a critical time in the evolution of Australia's flora and fauna when lush greenhouse conditions were giving way to a long, slow drying out that fundamentally reshaped the continent's cargo of life as rainforests retreated.

Dr Black notes that the Nimbadon skulls also reveal that early in life, the emphasis of its growth was on the development of bones at the front of the face, to help the baby to suckle from its mother. As it grew older and its diet changed to eating leaves, the rest of the skull developed and grew quite massive by way of a series of bony chambers surrounding the brain.

Team member Professor Mike Archer says: "Yet we found that its brain was quite small and stopped growing relatively early in its life. We think it needed a large surface area of skull to provide attachments for all the muscle power it required to chew large quantities of leaves, so its skull features empty areas, or sinus cavities. Roughly translated, this may be the first demonstration of how a growing mammal 'pays' for the need to eat more greens -- by becoming an 'airhead'.

"The abundance of Nimbadon fossils also suggests that they travelled in family groups or perhaps even larger gatherings: it's possible that this also reflects the beginning of mob behaviour in herbivorous marsupials, such as we see today in grey kangaroos."


Story Source:

The above story is based on materials provided by University of New South Wales. The original article was written by Bob Beale. Note: Materials may be edited for content and length.


Journal Reference:

  1. Karen H. Black; Michael Archer; Suzanne J. Hand; Henk Godthelp. First comprehensive analysis of cranial ontogeny in a fossil marsupial -- from a 15-million-year-old cave deposit in northern Australia. Journal of Vertebrate Paleontology, 2010; DOI: 10.1080/02724634.2010.483567

Cite This Page:

University of New South Wales. "Remarkable fossil cave shows how ancient marsupials grew." ScienceDaily. ScienceDaily, 18 July 2010. <www.sciencedaily.com/releases/2010/07/100715105951.htm>.
University of New South Wales. (2010, July 18). Remarkable fossil cave shows how ancient marsupials grew. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2010/07/100715105951.htm
University of New South Wales. "Remarkable fossil cave shows how ancient marsupials grew." ScienceDaily. www.sciencedaily.com/releases/2010/07/100715105951.htm (accessed July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins