Scientists from South Africa found 3.6 billion years Lampetra fossils
After Earth 3.6 billion years of tremendous changes, South Africa-find Lampetra fossils, we once again the "touch" to the number of bio-mass extinction "slip through", still survive in the most ancient fish.
At this coin 3.6 billion years of Lampetra fossils for study, the scientists will study results on October 26, the journal nature. This is the discovery of oldest fish fossils.Scientists in South Africa-find 3.6 billion years ago Lampetra fossils of recovery plans, its shape and today's Lampetra compared, it was difficult to see billions of years of evolution.
Monteggia in eel recovery of fossils and lines.
Figure b-modern Lampetra, a discovery for South Africa's Lampetra fossil recovery plan, its profile and modern Lampetra almost no difference, top head significantly wider.
South Africa
World's oldest fish fossils
South Africa Eastern Cape near Grahamstown witberge rocks, scientists found a fossil.
Fossil long only 42 mm, but the most important mouth shape features are clearly visible. Through scientific research, Robert · GESS (RobertW.Guss), researchers determine the fossil for survival 3.6 Lampetra for years.Appearance, Lampetra much like our eating eel or eel: body long, round, smooth not Jack, presently.
"But it's worse than we see all the fish is original because it hasn't, mandibular, you cannot use your mouth to chew food.
Estuary is a round disk. It has 7 of the slightly elliptical, eye Gill hole into the back row, a column "Institute of paleontology and paleoanthropology miman academician noted Lampetra" unique ". Miman precisely is this paper."It fossil is t
he Devonian Lampetra," said, "one tooth discovery is the first time, at the mouth of discovery is also a sucker for accident", said as Lampetra evolutionary history of the little-known, a new fossil discovery exciting. Prior to this, we trace the Lampetra evolution, that the survival of at least 300 million years. But this new discoveries, and the historical Lampetra step at least 3.6 billion years.In miman it seems that these pieces of new fossils preserved relatively intact, is found in the most distant Lampetra fossils, contribute to our research Lampetra evolutionary history.
China
Monteggia in eel to break the monopoly of "North America"
Because Lampetra only cartilage, bones, without scales, it is difficult to be saved as fossils, in its long history of life, the fossil record is extremely small and worn.
Break the records is in 1968, the United States scientists baldaque and Jennifer Siegel in Central Illinois United States from nearly 300 million years ago of the Carboniferous marine strata, found the first fossils Lampetra Meishi eel, as a new species.
The same year, Science magazine published this discovery.After 15 years, 1983 France scientists make-leaf rose together with United States scientists Lund published another species of Lampetra Harrington eel.
However, these two important discovery that fly in the ointment is that the fossil preservation, many features are difficult to verify."These two Lampetra fossils are 3 billion years or so," stated all along miman Lampetra found only in North America.
Break the "North American pattern" is found in China and biota Lampetra fossils.
Miman etc researchers study results have been published on 22 June in the journal nature. The fossils of ningcheng County, Inner Mongolia, China from the lower Cretaceous of Yixian, represents a new species: monteggia in eel. "The genus name indicates that it lives in the Mesozoic era," miman pointed out that, in the eel monteggia's new name is dedicated to the famous fish Shanghai fisheries University biologist Ms. Meng Qing Wen."Born in monteggia found previously in the eel, the Lampetra awareness only are born Lampetra and nearly 3 million years ago of save poor fossils.
While monteggia Lampetra is first found in the Mesozoic strata, and 1968, 1983 two fossils is more than the young fossils, "in an interview, said the miman on Chinese paleontologists is a pleasant surprise, monteggia's discovery in eel, Lampetra fossils in Earth history distribution extends from North America, Europe and Asia.
But in China after the surprise, new discoveries from South Africa, and to throw another Lampetra fossil.
Topic
Lampetra is agnatha ancestors?
Lampetra had and many old, no jaw fish classified together, known as "agnatha", these "agnatha" also has no jaw, single nostril, only two semicircular Canal and other features.
"Lampetra and blind eel is the only modern also survive in agnatha, or it may be the most primitive vertebrates.
" Miman pointed out that in the early and middle Paleozoic era (about 300 million-4 billion years), a variety of" agnatha "on the Earth is very prosperous. They used to be the ruler of Earth. Initially, Lampetra and blind eel collation was agnatha. But in the evolution of the Earth's long history, from the "agnatha" in certain typesDevelopment out of the current world, including human, are vertebrates agnatha.From agnatha the agnatha, evolution of the line between what? scientists generally we sketched out a picture picture: ancient ocean appears first agnatha spine fish-like animals, evolution as a after agnatha fish, including humans, are all vertebrates agnatha fish have evolved.
In recent years, research has shown that "agnatha" cannot be sui generis, that is, "agnatha" part types and in agnatha form a group.
"From fossils, from morphology, agnatha in a class, is Lampetra followed by agnatha collation. But more blind eel, more original, old, should be classified as a species. "Miman pointed out that the paleontology territories on agnatha and agnatha relationship between knowledge of the" revolution ", Lampetra is considered to be ranked with a jaw class to a class.However, even if Lampetra ascent of man, there is the oldest fossil of South Africa, agnatha how evolution is also just a hypothesis.
Lampetra in modern biotechnology has been regarded as agnatha ancestors, but also have existed many fossils agnatha, who have the most recent agnatha ancestors could not really sure, now it is the most precise, Lampetra and agnatha form a group. "Evolutionary process in the Middle, we have seen, nor do the experiment. We can only do the mutual relationship between the presumption, who and who recently, who with whom relations times past, and so on. "It seems the miman, Lampetra phylogenetic and agnatha is the origin of a hot topic of discussion and the outdoors, and successive fossil discoveries to research provided important information.Xiequ
Evolution of millions of years, does not see "Zhu Yan"
The history of the Earth, in addition to our well known dinosaur extinction period, there are a number of mass extinction event.
However, several mass extinction event, "contemporaneous" plants and animals are unable to escape the extinction of the disaster, Lampetra but still cruising the rivers, lakes, sea, until today. More magic, for up to 4 billion years of a long evolution process, Lampetra "appearance" basic didn't change.Mr. Mann, Academician to bridge the "fossil preservation is back down surface, therefore I propose to make a back-down-side of the recovery plan.
" Ultimately, back out of the dip surface recovery plan (see in the figure a). From here, from the top, look, we can see the evolution of grooved cut down. 3.6 million years ago of Lampetra front-end is very spacious, large head, mouth sucker is also particularly significant. "It's like a cylinder, behind physical sucker mouth flat, and the body more or less the same. ”However, even then, the evolutionary Lampetra is also extremely slow.
But so far in the 1.25 billion in the process of evolution Lampetra looks just didn't "aliasing", its shape is very close now students groups. "This shows it used up to 1 million years of evolution, evolutionary rates abnormally slow,"Miman pointed out, we can even stuck with the "evolution," a Word to describe this species.
■ Related links
Lampetra water "Vampire"
Lampetra lips is very strange, round like a sucker, there were sharp teeth, but there is no constructor for JAWS.
Lampetra in its early stages of ontogeny live in rivers or lakes in the bottom waters, use it as the sucker sucking mouth small animals. When it fully, the lifestyle is turned into a parasitic life, sucker-like mouth adsorption in other fish's body, then the file like sharp teeth to host open a hole on the file, and then got into the host body to take blood. Sometimes, Lampetra in host has not died before giving up on it and find another new victims; also sometimes Lampetra is parasitic on the fish's body until it died of blood spot.■ The Awakening Patch
Monteggia in eel
In 2005, Chinese Academy of Sciences and paleoanthropology researcher Wang Xiao Lin fieldwork in ningcheng County, Inner Mongolia, China, found a date when you saved the most complete Lampetra fossils found fossil miraculously preserved Lampetra full form.
As a result, the Group has invited fish fossils from the experts, academician miman came to study. Miman and her colleagues will this fossil named monteggia in eel, a name for the Shanghai famous fish biologist to Ms. Meng Qing Wen.22 June 2006 edition of the top-level scientific publications in the journal nature, reports the Chinese scientists will cross the waters of the Earth more than
300 million years of Lampetra fossils known as monteggia in eel.Interviews/reporter Li Jian-
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