Featured Research

from universities, journals, and other organizations

Filling The Gap In The Fossil Record

Date:
May 8, 2009
Source:
Geological Society of America
Summary:
The Neoproterozoic interval of "hidden" evolution refers to a gap of unknown duration between the time when animals first evolved (uncertain) and the oldest known fossil or geochemical evidence of animals (latest Neoproterozoic, about 600-650 million years ago).

The Neoproterozoic interval of "hidden" evolution refers to a gap of unknown duration between the time when animals first evolved (uncertain) and the oldest known fossil or geochemical evidence of animals (latest Neoproterozoic, about 600-650 million years ago).

Neuweiler et al. now propose to fill this gap. They describe distinctive, microscopic features in early Neoproterozoic limestone (between 779 and 1083 million years old) from the Northwest Territories of Canada, consisting of highly structured zones with multi-generational arrays of carbonate minerals, secondary voids, and internal sediment. Today, such a texture develops when aragonite crystals precipitate on the decaying connective tissue (collagen) of sponges in sediment on the sea floor.

As sponge decay progresses, a complex fabric of calcareous material and voids is produced, which is identical to fabrics in Phanerozoic limestones (less than 542 million years old) containing known sponge body fossils and to the fabrics now reported from the early Neoproterozoic.

Collagenous connective tissue is a fundamental character of all metazoans (animals), and so the presence in early Neoproterozoic rocks of a microscopic fabric directly associated with it implies that metazoan-grade organisms existed at that time.

These purported ancestral metazoans did not have a canal system that would relate them to sponges, the simplest form of animal known today. Instead, they likely represent a structured consortium of protists in a shared collagenous scaffold.

These results push back the earliest geologic evidence for animals by around 200 million years. This timing corroborates results of an integrated phylochronology and supports the concept of a biosphere that persisted through Snowball Earth.

This research was published in Geology by Fritz Neuweiler et al., in May 2009.


Story Source:

The above story is based on materials provided by Geological Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Geological Society of America. "Filling The Gap In The Fossil Record." ScienceDaily. ScienceDaily, 8 May 2009. <www.sciencedaily.com/releases/2009/05/090504151505.htm>.
Geological Society of America. (2009, May 8). Filling The Gap In The Fossil Record. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2009/05/090504151505.htm
Geological Society of America. "Filling The Gap In The Fossil Record." ScienceDaily. www.sciencedaily.com/releases/2009/05/090504151505.htm (accessed October 21, 2014).

Share This



More Fossils & Ruins News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Turns Out Jack The Ripper's True Identity Is Still Unknown

Turns Out Jack The Ripper's True Identity Is Still Unknown

Newsy (Oct. 20, 2014) After testing DNA from a shawl found near one of Jack the Ripper's victims, a scientist said he'd identified the killer. New reports refute the claim. Video provided by Newsy
Powered by NewsLook.com
Fish Fossil Shows First-Ever Sex Was Done Side By Side

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Newsy (Oct. 19, 2014) A 380-million-year-old fish may be the first creature to have copulative sex - and it was side by side with arms linked, like square dancers. Video provided by Newsy
Powered by NewsLook.com
As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

Newsy (Oct. 19, 2014) With Sweden on the look-out for a suspected Russian sub, a lot of people are talking about the Cold War, but is it an apt comparison? Video provided by Newsy
Powered by NewsLook.com
So, Kangaroos Didn't Always Hop

So, Kangaroos Didn't Always Hop

Newsy (Oct. 16, 2014) Researchers believe an extinct kangaroo species weighed 500 pounds or more and couldn't hop. 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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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