Featured Research

from universities, journals, and other organizations

Reptile Fossil Reignites Debate Over New Zealand Submergence

Date:
January 29, 2009
Source:
University College London - UCL
Summary:
The fossil of a lizard-like New Zealand reptile has been identified by a team of scientists. The fossil, dating back 18 million years, has triggered fresh arguments over whether the continent was fully submerged some 25 million years ago.

A humourous depiction of an ancestral tuatara (Sphenodon) sitting on an exaggeratedly small piece of land during the height of the debated submergence of New Zealand.
Credit: Photo by Alan J D Tennyson of a wild tuatara on Stanley Island; prepared and manipulated by Marc E H Jones.

The fossil of a lizard-like New Zealand reptile has been identified by a team of scientists from UCL (University College London), University of Adelaide, and the Museum of New Zealand Te Papa Tongarewa. The fossil, dating back 18 million years, has triggered fresh arguments over whether the continent was fully submerged some 25 million years ago.

Today, the endangered New Zealand tuatara (Sphenodon) is a lizard-like reptile that is the only survivor of a group that was globally widespread at the time of the dinosaurs. The tuatara lives on 35 islands scattered around the coast of New Zealand, mainland populations having become extinct with the arrival of humans and associated animals some 750 years ago.

The oldest known Sphenodon fossil dates to the Pleistocene era (around 34,000 years old), while the new discovery dates to the Early Miocene some 19 to 16 million years ago (Mya).The fossil, of jaws and dentition closely resembling those of the present-day tuatara, bridges a gap of nearly 70 million years in the fossil record of the group between the Late Pleistocene of New Zealand and the Late Cretaceous of Argentina.

In a paper published this week in the Proceedings of the Royal Society B, the team says that its findings offer further evidence that the ancestors of the tuatara have been on the landmass since it separated from the rest of the southern continents (Gondwana) some 82 Mya.

Lead author Dr Marc Jones, UCL Cell and Developmental Biology, says: "It has been argued that New Zealand was completely submerged during the Oligo-Miocene drowning of the continent some 25 to 22 million years ago (Mya). However, the diversity of fossils now known from the Miocene (St Bathans Fauna of the Manuherikia Group) suggests it is more likely that enough land remained above the water to ensure the survival of a number of species, such as frogs, kauri trees and several modern freshwater insects, as well as the tuatara."

“The fossil also provides the first direct evidence that the ancestors of the tuatara survived in New Zealand despite substantial climatic and environmental changes, such as a global temperature drop of some eight degrees celsius around 14 million years ago (Mid-Miocene).

“Between the Late Oligocene and earliest Miocene (35 to 22 Mya) a global sea-level rise submerged much of

New Zealand, but the question is, by how much? If the continent of Zealandia was completely submerged, the Sphenodon would have had to recolonize it by ocean rafting. If we look at the transoceanic capabilities of modern Sphenodon, it can swim, but only short distances; it is able to survive without food for several months, but dehydration would be a serious problem for a long journey because of high rates of water loss through the skin. Furthermore, there is currently no evidence of a population outside New Zealand at that time.

“It seems more likely that some local land surface persisted during the drowning of the continent and allowed the

ancestors of the tuatara along with some frogs, birds and mammals (known from the Miocene but now extinct) to survive the transgression, although the extent of the remaining land surface at the time is open to speculation. However, even if Zealandia was reduced to only one per cent of today’s surface area it would still represent over 2,500 square kilometres, well over 1,000 times the surface area of Stephen’s Island (1.5 km squared), where over 30,000 tuatara currently live.”


Story Source:

The above story is based on materials provided by University College London - UCL. Note: Materials may be edited for content and length.


Journal Reference:

  1. Marc Jones, Alan Tennyson, Jennifer Worthy, Susan Evans and Trevor Worthy. A sphenodontine (Rhynchocephalia) from the Miocene of New Zealand and palaeobiogeography of the tuatara (Sphenodon. Proceedings of the Royal Society B, 21 January 2009

Cite This Page:

University College London - UCL. "Reptile Fossil Reignites Debate Over New Zealand Submergence." ScienceDaily. ScienceDaily, 29 January 2009. <www.sciencedaily.com/releases/2009/01/090121092403.htm>.
University College London - UCL. (2009, January 29). Reptile Fossil Reignites Debate Over New Zealand Submergence. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2009/01/090121092403.htm
University College London - UCL. "Reptile Fossil Reignites Debate Over New Zealand Submergence." ScienceDaily. www.sciencedaily.com/releases/2009/01/090121092403.htm (accessed April 17, 2014).

Share This



More Fossils & Ruins News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Erotic Art Offers Glimpse of China's 'lost' Sexual Philosophy

Erotic Art Offers Glimpse of China's 'lost' Sexual Philosophy

AFP (Apr. 16, 2014) Explicit Chinese art works dating back centuries go on display in Hong Kong, revealing China's ancient relationship with sex. Video provided by AFP
Powered by NewsLook.com
French Historians Fight to Save Iconic La Samaritaine Buildings

French Historians Fight to Save Iconic La Samaritaine Buildings

AFP (Apr. 15, 2014) Parisians and local historians are fighting to save one of the French capital's iconic buildings, the La Samaritaine department store. Duration: 01:42 Video provided by AFP
Powered by NewsLook.com
Bee Fossils Provide Insight Into Ice Age Environment

Bee Fossils Provide Insight Into Ice Age Environment

Newsy (Apr. 12, 2014) Archeologists have found many fossils in the La Brea Tar Pits, including those of saber-tooth tigers and mammoths. Video provided by Newsy
Powered by NewsLook.com
Daddy Longlegs Once Had 4 Eyes

Daddy Longlegs Once Had 4 Eyes

Newsy (Apr. 11, 2014) A new fossil has revealed daddy longlegs one had an extra pair of eyes. Modern species retain the gene for the extra pair but never develop them. Video provided by Newsy
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