Scientists have excavated the largest dinosaur изкопаемо which would have been the largest terrestrial animal on our планета.
Екип от учени от Южна Африка, Обединеното кралство и Бразилия, водени от Университета на Витватерсранд, откриха a изкопаемо на нов вид на динозавър в Южна Африка се смята, че е свързан с бронтозавъра. Този ранен юрски динозавър тежеше огромните 26,000 XNUMX паунда, т.е. двойно по-голям от африкански слон, и стои четири метра на бедрата. Наречен е „Ledumahadi mafube“, което означава „гигантски гръм при зазоряване“ на местния език сесото на региона, където е открит.
Еволюционен преход
Ledumahadi е тясно свързан с динозаврите завроподи, включително добре познатите видове Brontosaurus и Diplodocus. Беше растителноядно тревопасно животно, имаше дебели крайници и беше четириноги, т.е. ходеше на четирите си крака в поза, подобна на съвременните слонове. В сравнение с дългите, тънки колонообразни крайници на завропод, предните крайници на Ледумахади са по-приклекнати, т.е. има по-огънати крайници като примитивните динозаври. Техните предци са ходили само на два крака и сигурно са се приспособили да ходят и на четирите и затова са станали по-големи, за да поддържат храносмилането, тъй като са били тревопасни.
Researchers compared изкопаемо data from dinosaurs, reptiles etc who walked on two or four legs and they measured limb size and thickness. This is how they concluded Ledumahadi’s posture and its way of walking on all four limbs. It is understood that many other dinosaurs must have experimented walking on all four limbs which could optimally balance a bigger body. Based upon these collective observations, researchers say that Ledumahadi was definitely a ‘transitional’ dinosaur, as it had ‘crouched’ yet very thick limbs to support its large body. Their limb bones– both arms and legs – are very robust and similar in shape to giant sauropod dinosaurs but obviously thicker while sauropods had more slender limbs. The evolution of four-legged postures came before their giant bodies. Just sheer size and elephant-like limb posture helped them, example sauropods, to become one of the most dominant dinosaur groups during the Jurassic era. Ledumahadi definitely represents a transitional stage between two major groups of dinosaurs. The group of early dinosaurs were experimenting with various ways of becoming bigger in size during the first tens of millions of years of their evolution. What it means for research is that the evolutionary transition from a small, bipedal creature to a large, quadrupled sauropod is a complex path and this evolution certainly led to survival and achieving dominance.
The discovery published tells us that even more than 200 million years ago, these dinosaurs were the largest vertebrates to be present on the планета, and this time period was almost 40-50 million years earlier than giant sauropods were first seen. The new dinosaur is closely related to giant dinosaurs who lived in Argentina around that time supporting the idea that all continents that we see today were assembled as Pangea – a supercontinent comprised of world’s land mass during Early Jurassic. And at that time this region of South Africa was not mountainous as we see it today but was flat and semi-arid with shallow streams. Certainly, it was a thriving ecosystem. Like Ledumahadi, many other dinosaurs – both giant and tiny – roamed the place at the time. It is fascinating that South Africa has helped to understand the rise of giant dinosaurs during Jurassic era.
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Източник (и)
McPhee BW et al 2018. Гигантски динозавър от най-ранния юрски период на Южна Африка и преходът към четириноги в ранните завроподоморфи. наука. 28 (19). https://doi.org/10.1016/j.cub.2018.07.063
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