Featured Research

from universities, journals, and other organizations

Oldest fossil hominin ear bones ever recovered: Discovery could yield important clues on human origins

Date:
May 13, 2013
Source:
Binghamton University
Summary:
Anthropologists could shed new light on the earliest existence of humans. The study analyzed the tiny ear bones, the malleus, incus and stapes, from two species of early human ancestor in South Africa.

Tiny ear bones (from left) the incus, stapes, and malleus could provide big clues to human evolution.
Credit: Texas A&M

A new study, led by a Binghamton University anthropologist and published this week by the Proceedings of the National Academy of Sciences, could shed new light on the earliest existence of humans. The study analyzed the tiny ear bones, the malleus, incus and stapes, from two species of early human ancestor in South Africa. The ear ossicles are the smallest bones in the human body and are among the rarest of human fossils recovered.

Unlike other bones of the skeleton, the ossicles are already fully formed and adult-sized at birth. This indicates that their size and shape is under very strong genetic control and, despite their small size, they hold a wealth of evolutionary information.

The study, led by Binghamton University anthropologist Rolf Quam, was carried out by an international team of researchers from institutions in the US, Italy and Spain. They analyzed several auditory ossicles representing the early hominin species Paranthropus robustus and Australopithecus africanus. The new study includes the oldest complete ossicular chain (i.e. all three ear bones) of a fossil hominin ever recovered. The bones date to around two million years ago and come from the well-known South African cave sites of Swartkrans and Sterkfontein, which have yielded abundant fossils of these early human ancestors.

The researchers report several significant findings from the study. The malleus is clearly human-like, and its size and shape can be easily distinguished from our closest living relatives, chimpanzees, gorillas and orangutans. Many aspects of the skull, teeth and skeleton in these early human ancestors remain quite primitive and ape-like, but the malleus is one of the very few features of these early hominins that is similar to our own species, Homo sapiens. Since both the early hominin species share this human-like malleus, the anatomical changes in this bone must have occurred very early in our evolutionary history. Says Quam, "Bipedalism (walking on two feet) and a reduction in the size of the canine teeth have long been held up as the "hallmark of humanity" since they seem to be present in the earliest human fossils recovered to date.

Our study suggests that the list may need to be updated to include changes in the malleus as well." More fossils from even earlier time periods are needed to corroborate this assertion, says Quam. In contrast to the malleus, the two other ear ossicles, the incus and stapes, appear more similar to chimpanzees, gorillas and orangutans. The ossicles, then, show an interesting mixture of ape-like and human-like features.

The anatomical differences from humans found in the ossicles, along with other differences in the outer, middle and inner ear, are consistent with different hearing capacities in these early hominin taxa compared to modern humans. Although the current study does not demonstrate this conclusively, the team plans on studying the functional aspects of the ear in these early hominins relying on 3D virtual reconstructions based on high resolution CT scans. The team has already applied this approach previously to the 500,000 year-old human fossils from the Sierra de Atapuerca in northern Spain. The fossils from this site represent the ancestors of the Neandertals, but the results suggested their hearing pattern already resembled Homo sapiens. Extending this type of analysis to Australopithecus and Paranthropus should provide new insight into when our modern human pattern of hearing may have evolved.


Story Source:

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


Journal Reference:

  1. Rolf M. Quam, Darryl J. de Ruiter, Melchiorre Masali, Juan-Luis Arsuaga, Ignacio Martνnez, and Jacopo Moggi-Cecchi. Early hominin auditory ossicles from South Africa. PNAS, May 13, 2013 DOI: 10.1073/pnas.1303375110

Cite This Page:

Binghamton University. "Oldest fossil hominin ear bones ever recovered: Discovery could yield important clues on human origins." ScienceDaily. ScienceDaily, 13 May 2013. <www.sciencedaily.com/releases/2013/05/130513174331.htm>.
Binghamton University. (2013, May 13). Oldest fossil hominin ear bones ever recovered: Discovery could yield important clues on human origins. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2013/05/130513174331.htm
Binghamton University. "Oldest fossil hominin ear bones ever recovered: Discovery could yield important clues on human origins." ScienceDaily. www.sciencedaily.com/releases/2013/05/130513174331.htm (accessed August 20, 2014).

Share This




More Fossils & Ruins News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Newsy (Aug. 15, 2014) — A mother and son in Alaska uncovered woolly mammoth tusks in the same river more than two decades apart. Video provided by Newsy
Powered by NewsLook.com
Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Newsy (Aug. 14, 2014) — Newly found fossils reveal a previously unknown species of flying reptile with a really weird head, which some say looks like a butterfly. Video provided by Newsy
Powered by NewsLook.com
Clearing WWII's Explosive Legacy in the Pacific

Clearing WWII's Explosive Legacy in the Pacific

AFP (Aug. 11, 2014) — The hulks of tanks can still be found rusting in the jungles of Palau, but the fierce fighting that scarred the Pacific island nation in WWII has left a more dangerous legacy - unexploded bombs that pose a constant risk to locals. Duration: 00:47 Video provided by AFP
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:

More Coverage


Prehistoric Ear Bones Could Lead to Evolutionary Answers

May 13, 2013 — The tiniest bones in the human body -- the bones of the middle ear -- could provide huge clues about our evolution and the development of modern-day humans, according to ... read more
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