Hynerpeton
Encyclopedia
Hynerpeton was a basal carnivorous tetrapod
that lived in the lakes and estuaries of the Late Devonian
period around 360 million years ago. Like many primitive tetrapods, it is sometimes referred to as an "amphibian", though it is not a true member of the modern Lissamphibia
. The Late Devonian
saw the evolution of plants into trees and growing into vast forests pumping oxygen into the air, possibly giving Hynerpeton an edge because it evolved complex lungs to exploit it. Its lungs probably consisted of sacs like modern terrestrial vertebrates. In 1993, the paleontologist
s Ted Daeschler
and Neil Shubin
found the first Hynerpeton fossil, a shoulder bone, near Hyner, Pennsylvania. They were surveying the Devonian rocks of Pennsylvania in search of fossil evidence for the origin of animal limbs. The animal had a very robust shoulder, which indicated that it had powerful appendages. Only a few bones have been found from Hynerpeton, in Red Hill
, Pennsylvania
, U.S.A.. The known fossils include two shoulder girdles, two lower jaws, a jugal
bone and some gastralia
.
The structure of the shoulder girdle indicates this animal may have been one of the earlier, more primitive tetrapods to evolve during the Devonian. Information on the relationship of the known fossils of Hynerpeton to other Devonian tetrapods can be found in Gaining Ground The Origin and Evolution of Tetrapods by Jennifer A. Clack
.
It is thought that that these early amphibians are descended from lobe-finned fish, such as Hyneria
, whose stout fins evolved into legs and their swim bladder into lungs. It is still not known whether Hynerpeton is the direct ancestor to all later backboned land animals (including humans), but the fact that it had eight fingers, not five, suggests that it is simply our evolutionary cousin.
. It was seen fancifully and erroneously evolving from Cephalaspis
, and then walking on land. One of the Hynerpeton meets a gruesome end when a predatory Hyneria
fish ambushes it at the water's edge, shortly after a mating session with a female Hynerpeton. Its eggs evolved into those of Petrolacosaurus
.
. Pg. 30-31. Canada: Firefly Books Ltd., 2006
Tetrapod
Tetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...
that lived in the lakes and estuaries of the Late Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
period around 360 million years ago. Like many primitive tetrapods, it is sometimes referred to as an "amphibian", though it is not a true member of the modern Lissamphibia
Lissamphibia
The subclass Lissamphibia includes all recent amphibians and means smooth amphibia.Extant amphibians fall into one of three orders — the Anura , the Caudata or Urodela , and the Gymnophiona or Apoda .Although the ancestry of each group is still unclear, all share certain common characteristics,...
. The Late Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
saw the evolution of plants into trees and growing into vast forests pumping oxygen into the air, possibly giving Hynerpeton an edge because it evolved complex lungs to exploit it. Its lungs probably consisted of sacs like modern terrestrial vertebrates. In 1993, the paleontologist
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
s Ted Daeschler
Ted Daeschler
Ted Daeschler is an American vertebrate paleontologist and Associate Curator and Chair of Vertebrate Biology at the Academy of Natural Sciences in Philadelphia...
and Neil Shubin
Neil Shubin
Neil Shubin is an American paleontologist, evolutionary biologist and popular science writer. He is the Robert R. Bensley Professor of Organismal Biology and Anatomy, Associate Dean of Organismal Biology and Anatomy and Professor on the Committee of Evolutionary Biology at the University of...
found the first Hynerpeton fossil, a shoulder bone, near Hyner, Pennsylvania. They were surveying the Devonian rocks of Pennsylvania in search of fossil evidence for the origin of animal limbs. The animal had a very robust shoulder, which indicated that it had powerful appendages. Only a few bones have been found from Hynerpeton, in Red Hill
Red Hill, Pennsylvania
Red Hill is a borough in Montgomery County, Pennsylvania, United States, and is primarily a lake shore lowlands suburban community northwest of Philadelphia in the Delaware River Valley watershed, as is the balance of its county...
, Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, U.S.A.. The known fossils include two shoulder girdles, two lower jaws, a jugal
Jugal
The jugal is a skull bone found in most reptiles, amphibians, and birds. In mammals, the jugal is often called the malar or Zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species....
bone and some gastralia
Gastralium
Gastralia are dermal bones found in the ventral body wall of crocodilian and Sphenodon species. They are found between the sternum and pelvis, and do not articulate with the vertebrae...
.
The structure of the shoulder girdle indicates this animal may have been one of the earlier, more primitive tetrapods to evolve during the Devonian. Information on the relationship of the known fossils of Hynerpeton to other Devonian tetrapods can be found in Gaining Ground The Origin and Evolution of Tetrapods by Jennifer A. Clack
Jennifer A. Clack
Jennifer Alice Clack, FRS, is an English paleontologist, an expert in the field of evolutionary biology. She studies the "fish to tetrapod" transition— the origin, evolutionary development and radiation of early tetrapods and their relatives among the lobe-finned fishes...
.
It is thought that that these early amphibians are descended from lobe-finned fish, such as Hyneria
Hyneria
Hyneria was a prehistoric predatory lobe-finned fish that lived during the Devonian period around 360 million years ago. It was approximately 4 meters in length and weighed as much as two tons...
, whose stout fins evolved into legs and their swim bladder into lungs. It is still not known whether Hynerpeton is the direct ancestor to all later backboned land animals (including humans), but the fact that it had eight fingers, not five, suggests that it is simply our evolutionary cousin.
In popular culture
Hynerpeton is featured in the first episode of the 2005 documentary series Walking with MonstersWalking with Monsters
Walking with Monsters is a three-part British documentary film series about life in the Paleozoic, bringing to life extinct arthropods, fish, amphibians, synapsids, and reptiles...
. It was seen fancifully and erroneously evolving from Cephalaspis
Cephalaspis
Cephalaspis was a genus of armored goldfish-sized to trout-sized detritivorous fish that lived in freshwater streams and estuaries of early Devonian Western Europe...
, and then walking on land. One of the Hynerpeton meets a gruesome end when a predatory Hyneria
Hyneria
Hyneria was a prehistoric predatory lobe-finned fish that lived during the Devonian period around 360 million years ago. It was approximately 4 meters in length and weighed as much as two tons...
fish ambushes it at the water's edge, shortly after a mating session with a female Hynerpeton. Its eggs evolved into those of Petrolacosaurus
Petrolacosaurus
Petrolacosaurus was a small, long, reptile, and the earliest diapsid known. It lived during the late Carboniferous period, the Joggins strata where it was found are dated to 302 million years old....
.
Sources
Tim Haines, and Paul Chambers. The Complete Guide to Prehistoric LifeThe Complete Guide to Prehistoric Life
The Complete Guide to Prehistoric Life is an encyclopedia featuring 111 of the prehistoric animals from the Walking With... series, as well as an additional one . It was published in 2006 by Firefly Books, and written by Tim Haines with Paul Chambers...
. Pg. 30-31. Canada: Firefly Books Ltd., 2006