When vertebrates climb from the water onto land, they are confronted with a strange new world. Vertebrates measure the earth with their limbs, explore plains and mountains within sight, and life is about to sweep across the desolate earth! We have been exploring the history of early upright walking in vertebrates, and recently scientists have used bionic robots to reproduce the walking patterns of early tetrapods, and this study has revised our understanding of the origin of tetrapod walking.
Amphibians on the highlands
Picture note: The German town of Gotha is a small town with a strong traditional flavor, the picture comes from the Internet
The town of Gotha is located in central Germany and the image comes from the Internet
There is a small town in southern Germany called Gotha, which is surrounded by the famous thuringian forest. 20 kilometers south of the town of Gotha, there is a quarry called bromacker, and the quarry's formation belongs to the Permian period, and the formation preserves a large number of ancient life relics from more than 290 million years ago.
Photo note: Paleontologist looking for fossils in a quarry, image from the web
Photo note: Amphibian fossils found in the quarry, picture from the network
In 1998, paleontologists found a fossil (number: mng 10181) at the Bromacker Quarry, which is very well preserved and the limb structure is clearly visible. After research, paleontologists published a paper in the bulletin of the carnegie museum of natural history, "A new diadectid (diadectomorpha), orobates pabsti, from the early plesiology in central Germany permian of central germany）。 The fossils of " Apatosaurus " came from the tambach formation , about 290 million years ago.
Photo note: Fossils of The Mountain Dragon, picture from the Internet
The genus name "orobates" comes from the Greek words "oros" (meaning "mountain") and "bates" (meaning "walking" because researchers believe the animal was active in a highland environment. The model species name of The mountain dragon is orobates pabsti, and the species name "pabsti" is dedicated to W. Pabsti, who made outstanding contributions to the study of quarry fossils. pabst）。 Although fossilized , " " " Apatosaurus " resembled a reptile , the suborder " Obtucenosaurus " was a branch of amphibians.
According to the complete fossils, the body length of the mountainosaurus can reach 1 meter and the weight is about 4 kilograms. It had a shorter head and large teeth in its mouth, and fed on plants with thicker fibers. The body was broad, the tail was slender, and the skin resembled today's giant salamander. From the skeleton, the limbs of the mountain dragon are strong, with five thick fingers on the limbs. Referring to today's amphibians, paleontologists believe that the mountain dragon should crawl on land like today's giant salamander, with its abdomen completely close to the ground, so its mobility on land is greatly limited.
Image note: Fossil line diagram of The Mountain Dragon, picture from the Network
Photo note: Early restoration of The Mountain Dragon, picture from the Internet
Photo note: The mountain dragon may be very similar to the giant salamander, the image comes from the Internet
Footprints and uprights
Image note: Fossil footprints of The Mountain Dragon, picture from the Internet
The fossils of The diplodocus are very complete, and their footprint fossils have been found together. Through the study of footprint fossils, paleontologists have overturned previous speculations, arguing that " Diplodocus " was not crawling on the ground , but probably had erect limb structures.
Photo note: Paleontologists are scanning fossils of Apatosaurus, pictured from the Web
Illustration: A three-dimensional skeletal reconstruction of a fossil of Apatosaurus, pictured from the Web
It was because of the discovery of footprint fossils that paleontologists began to reconsider the deformation of rock formations during fossil formation and the state of preservation of the surrounding rocks that influenced the fossils in their original appearance, and whether this influence hindered the accurate reconstruction of the anatomy of Theodonosaurus. Through three-dimensional reconstruction, microfocus computed tomography was used to restore fragmented fossil bones of Apatosaurus to assess its weight, center of gravity, and mobility of its shoulder and hip joints. The findings suggest that It is likely that It had an upright limb structure, rather than the previously speculated giant salamander clinging to the ground, with its body center of gravity on the hip joint and hind limbs.
The study, published in the September 2015 issue of the journal Plos One, was titled "Three-dimensional skeletal reconstruction of the stem amniote orobates pabsti (diadectidae): analyses of body mass, centre of mass position, and joint mobility）。
Illustration: A three-dimensional skeleton reconstruction of the upright posture of The Mountain Dragon, picture from the network
Illustration: Reconstructed model of the skeleton of an upright walking mountain dragon, picture from the network
Image Note: The footprints of the mountain dragon indicate that it should be walking upright, and the image comes from the network
Resurrect the Mountain Dragon with a robot
John nyakatura, an evolutionary biologist at Humboldt University in Berlin, image from the web
Paleontologists' research has shown that the mountain dragon has a gait of walking upright on all fours, but the details of how this gait operates and how it leaves matching footprints are still fascinating. To unravel the mystery, john nyakatura, an evolutionary biologist from Humboldt University in Berlin, and kamilo melo, a roboticist at the Swiss Federal Institute of Technology in Lausanne, formed a research team that combined paleontology, biomechanics, computer simulations, animal live demonstrations and bionic robots to create a mountain dragon bionic robot called "orobot".
Image note: orobot, picture from the network
Image note: Orobot top view, image from the network
Orobot looks very rough, but in fact very precise, it is based on the skeleton of the mountain dragon, there are eight drive joints in the entire spine, can achieve natural curvature of the spine, there are five drives on each leg, can simulate different forms of movement. In the experiment, the researchers asked orobots to walk in a variety of gaits, with footprints left by the pattern of upright limbs and tails not mopping the ground, which perfectly matched the footprint fossils, proving that they walked like caimans today.
Image note: Orobot undergoing testing, picture from the network
Illustration: Orobot (top) and the skeleton of the mountain dragon (bottom) show the picture, the picture is from the network
Image note: Orobot's footprints match the footprint fossils, and the image comes from the Internet
The related study on orobot was published in the journal Nature in January 2019 under the title "Reverse-engineering the locomotion of a stem amniote." The significance of this study is to prove that early tetrapods (amphibians) walked upright earlier than our previous studies, this advanced upright walking pattern existed before the emergence of amnioids, and the taxa of Apatosaurus had a very close evolutionary relationship with amniotics, so amniotic upright walking was not independently evolved, but inherited from amphibians.
conclusion
The use of bionic robots to restore and study paleontology is a pioneering achievement, and the study itself proves that early terrestrial vertebrates adapt to the environment and the evolution of motion much faster than we expected, and that the combination of bionic robots and paleontology will have broader applications in the future exploration of the evolution of life on Earth.
Resources:
1.berman, d. berman, d. s, henrici, ac, kissel, r., sumida, ss, and martens, t. s, henrici, ac, kissel, r., sumida, ss, and martens, t. (2004): a new diadectid (diadectomorpha), orobates pabsti, from the early permian of central germany. bulletin of the carnegie museum of natural history no 35: pp 1-37. abstract]
2.nyakatura, john a.; allen, vivian r.; lauströer, jonas; andikfar, amir; danczak, marek; ullrich, hans-jürgen; hufenbach, werner; martens, thomas; fischer, martin s. (10 september 2015). "a three-dimensional skeletal reconstruction of the stem amniote orobates pabsti (diadectidae): analyses of body mass, centre of mass position, and joint mobility". plos one. 10 (9): e0137284. doi:10.1371/journal.pone.0137284. pmc 4565719. pmid 26355297.
3.berman, d.s.; henrici, a.c. (september 2007). "first well-established track-trackmaker association of paleozoic tetrapods based on ichniotherium trackways and diadectid skeletons from the lower permian of germany". journal of vertebrate paleontology. 27 (3): 553–570. doi:10.1671/0272-4634(2007)27[553:fwtaop]2.0.co;2.
4.nyakatura, john; melo, kamilo; horvat, tomislav; karakasiliotis, kostas; r. allen, vivian; andikfar, amir; andrada, emanuel; arnold, patrick; lauströer, jonas; r. hutchinson, john; s. fischer, martin; j. ijspeert, auke (16 january 2019). "reverse-engineering the locomotion of a stem amniote". nature. 565. doi:10.1038/s41586-018-0851-2. eissn 1476-4687.
5.baker, noah (16 january 2019). "watch: robot reveals how ancient reptile ancestor moved". nature. retrieved 18 january 2019.
Image / Network (Intrusion and Deletion)
Text / Jiang's Little Thief Dragon (Jiang Hong)
Typography / Jiang's Little Thief Dragon