Featured Research

from universities, journals, and other organizations

Mammalian brain size influences development of individual cranial bones

Date:
April 9, 2014
Source:
University of Zurich
Summary:
In mammals, embryonic cranial development is modular and step-wise: The individual cranial bones form according to a defined, coordinated schedule. The typical increase in the size of the brain in mammals in the course of evolution ultimately triggered changes in this developmental plan, as a study conducted on embryos of 134 species of animal reveals.

This shows the different stages of skull development in the Japanese field mouse.
Credit: UZH

In mammals, embryonic cranial development is modular and step-wise: The individual cranial bones form according to a defined, coordinated schedule. The typical increase in the size of the brain in mammals in the course of evolution ultimately triggered changes in this developmental plan, as a study conducted on embryos of 134 species of animal headed by palaeontologists from the University of Zurich reveals.

Embryonic development in animals -- except mice and rats -- remains largely unexplored. For a research project at the University of Zurich, the embryos of 134 species of animal were studied non-invasively for the first time using microcomputer imaging, thus yielding globally unique data. The embryos studied came from museum collections all over the world. The international team of researchers headed by Marcelo Sánchez-Villagra especially studied cranial formation and discovered that the individual cranial bones develop in different phases that are characteristic for the individual species. According to the study, which was published in the journal Nature Communications, how the cranial bones develop in mammals also depends on brain size.

Brain size influences the timing of cranial development

The skulls of full-grown animals consist of many individual bones that have fused together. There are two types of bone: dermal and endochondral bones. Endochondral bones form from cartilaginous tissue, which ossifies in the course of the development. Dermal bones, on the other hand, are formed in the dermis. The majority of the skull consists of dermal bones. The bones inside the skull and the petrous bone, part of the temporal bone, however, are endochondral.

As Daisuke Koyabu, now at University of Tokyo, who conducted the studies while he was a post-doc under Sánchez-Villagra, was able to demonstrate, the different bone types do not develop synchronously: Dermal cranial bones form before the endochondrals. According to Sánchez-Villagra, this indicates that the individual bones form based on a precisely defined, coordinated schedule that is characteristic for every species of animal and enables conclusions to be drawn regarding their evolutionary relationships in the tree of animal life. The researchers also discovered that individual bones in the area around the back of the head have changed their development plan in the course of evolution. "The development of larger brains in mammals triggered the changes observed in the development of bone formation," Sánchez-Villagra.

Mammals: masticatory apparatus first

With the aid of quantitative methods and evolutionary trees, the researchers ultimately reconstructed the embryonic cranial development of the last common ancestors of all mammals, which lived 180 million years ago during the Jurassic period. As with the majority of mammals, its cranial development began with the formation of the masticatory apparatus bones.


Story Source:

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


Journal Reference:

  1. Daisuke Koyabu, Ingmar Werneburg, Naoki Morimoto, Christoph P. E. Zollikofer, Analia M. Forasiepi, Hideki Endo, Junpei Kimura, Satoshi D. Ohdachi, Nguyen Truong Son, Marcelo R. Sánchez-Villagra. Mammalian skull heterochrony reveals modular evolution and a link between cranial development and brain size. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4625

Cite This Page:

University of Zurich. "Mammalian brain size influences development of individual cranial bones." ScienceDaily. ScienceDaily, 9 April 2014. <www.sciencedaily.com/releases/2014/04/140409093941.htm>.
University of Zurich. (2014, April 9). Mammalian brain size influences development of individual cranial bones. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/04/140409093941.htm
University of Zurich. "Mammalian brain size influences development of individual cranial bones." ScienceDaily. www.sciencedaily.com/releases/2014/04/140409093941.htm (accessed September 1, 2014).

Share This




More Fossils & Ruins News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Millions Of Historical Public Domain Photos Added To Flickr

Millions Of Historical Public Domain Photos Added To Flickr

Newsy (Aug. 30, 2014) — Historian Kalev Leetaru uploaded a large collection of historical photos, images that were previously difficult to collect. Video provided by Newsy
Powered by NewsLook.com
Minds Blown: Scientists Develop Fish That Walk On Land

Minds Blown: Scientists Develop Fish That Walk On Land

Newsy (Aug. 28, 2014) — Canadian scientists looking into the very first land animals took a fish out of water and forced it to walk. Video provided by Newsy
Powered by NewsLook.com
Huge Ancient Wine Cellar Found In Israel

Huge Ancient Wine Cellar Found In Israel

Newsy (Aug. 28, 2014) — An international team uncovered a large ancient wine celler that likely belonged to a Cannonite ruler. Video provided by Newsy
Powered by NewsLook.com
40,000-Year-Old Mammoth Skeleton Found On Texas Farm

40,000-Year-Old Mammoth Skeleton Found On Texas Farm

Newsy (Aug. 26, 2014) — A mammoth skeleton was discovered in a gravel pit on Wayne McEwen's Texas farm back in May. It's now being donated to a museum. 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