Navigation Links
Ancient amphibians evolved a bite before migrating to dry land

Ancient aquatic amphibians developed the ability to feed on land before completing the transition to terrestrial life, researchers from Harvard University report this week in the Proceedings of the National Academy of Sciences.

Their work is based on analysis of the skulls of the first amphibians, which arose 375 million years ago, and their fish ancestors. The shapes of the junctions between adjacent skull bones -- termed "sutures" -- in the tops of these fish and amphibian skulls reveal how these extinct animals captured prey, say authors Molly J. Markey and Charles R. Marshall.

"Based on experimental data obtained from living fish, we found that the shapes of sutures in the skull roof indicate whether a fish captures its prey by sucking it into the mouth -- like a goldfish -- or by biting on it directly, like a crocodile," says Markey, a postdoctoral researcher and lecturer in Harvard's Department of Earth and Planetary Sciences. "A biting or chewing motion would result in a faint pushing together of the frontal bones in the skull, while a sucking motion would pull those bones ever so slightly apart. By comparing the skull roofs of living fish to those of early amphibians and their fishy ancestors, we were able to determine whether the fossil species fed by suction or by biting."

Using this approach, Markey and Marshall found that in one key transitional species, the aquatic amphibian Acanthostega, the shapes of the junctions between adjacent skull bones are consistent with biting prey. This finding, the scientists say, suggests that the water-dwelling Acanthostega may have bitten on prey at or near the water's edge.

"Going from the aquatic realm to land involved a series of adaptations to facilitate changes in locomotion, respiration, reproduction, sensation, and feeding," Markey says. "In water, suction is an efficient method of feeding, but it does not work in the much less dense air environment. Early terrestrial inhabitan ts would thus have had to develop the means for chomping prey."

Markey and Marshall first measured the skull roof sutures, those areas where the bones of the skull roof meet, in the living fish Polypterus as it fed. They then analyzed the same cranial junctions in several fossils -- the early amphibian Acanthostega, its fishy ancestor Eusthenopteron, and the extinct terrestrial amphibian Phonerpeton -- to determine how these bones may have moved relative to each other during feeding. By analyzing the tiny forces that the sutures experienced during feeding, such as tension or compression, the researchers could determine how the skull roof likely deformed as the animals ate.

Living fish exhibit an incredible array of tooth and jaw shapes, suggesting that, ironically, direct analysis of fossil jaws would be a less precise means of determining the feeding methods of extinct species, Markey says.

"Analysis of the sutures of the early amphibian species Acanthostega revealed that, while it had many adaptations to an aquatic lifestyle, it was more likely a biter than a sucker," Markey says. "The analysis suggests that amphibians evolved a bite before emerging onto land as fully terrestrial animals."


Source:Harvard University

Related biology news :

1. Ancient olfaction protein is shared by many bugs, offering new pest control target
2. Ancient immune defense mechanism is no match for HIV-1
3. Ancient DNA helps clarify the origins of two extinct New World horse species
4. Researchers Discover Ancient Origins Of Tuberculosis-causing Bacteria
5. Ancient DNA confirms single origin of Malagasy primates
6. Ancient anthropoid origins discovered in Africa
7. Ancient trans-Atlantic swarm brought locusts to the New World
8. Ancient humans brought bottle gourds to the Americas from Asia
9. Ancient DNA helps UF researchers unearth potential hemophilia therapy
10. Ancient DNA provides clues to the evolution of social behavior
11. Ancient ants arose 140-168 million years ago
Post Your Comments:

(Date:11/17/2015)... , Nov. 17, 2015  Vigilant Solutions announces today ... its Board of Directors. --> ... recently retiring from the partnership at TPG Capital, one ... with over $140 Billion in revenue.  He founded and ... all the TPG companies, from 1997 to 2013.  In ...
(Date:11/12/2015)... , Nov. 11, 2015   Growing need ... analytical tools has been paving the way for ... determination of discrete analytes in clinical, agricultural, environmental, ... being predominantly used in medical applications, however, their ... sectors due to continuous emphasis on improving product ...
(Date:11/9/2015)... 2015  Synaptics Inc. (NASDAQ: SYNA ), the ... entry into the automotive market with a comprehensive and ... of consumer electronics human interface innovation. Synaptics, industry-leading touch ... the automotive industry and will be implemented in numerous ... , Japan , and ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Telbec/ - ProMetic Life Sciences Inc. (TSX: PLI) (OTCQX: PFSCF) ... Laurin , President and Chief Executive Officer of ProMetic, will ... 27 th Annual Healthcare Conference to be held at ... st , at 8.50am (ET) and ProMetic,s management ... The presentation will be available live via a webcast accessible ...
(Date:11/24/2015)... Va. , Nov. 24, 2015 ... focused on discovering drugs for metabolic disorders, announced ... to its Board of Directors (BOD). Mr. ... officer of Human Genome Sciences (HGS), and also ... Organization. Jim Powers , Chairman and ...
(Date:11/24/2015)... and NEW YORK , November 24, ... investment by Bristol-Myers Squibb in a European ... Bristol-Myers Squibb Company in which the companies will work ... immuno-oncology and other areas of unmet medical need. The collaboration ... LSP 5, the latest LSP fund. This is the first ...
(Date:11/24/2015)... -- According to two new studies, fewer men are having ... many doctors, scientists, and public health experts have been pushing ... tests being done, will there be more men dying of ... "Despite the efforts made in regards to early detection ... cause of death in men, killing approximately 27,500 men this ...
Breaking Biology Technology: