Another major discovery was made in

Another major discovery was made in Egypt in 1989. Several skeletons of another early whale, Basilosaurus, were found in sediments left by the Tethys Sea and now exposed in the Sahara desert. This whale lived around 40 million years ago, 12 million years after Pakicetus. Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes. Such legs would have been far too small to have supported the 50-foot-long Basilosaurus on land. Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs.
An even more exciting find was reported in 1994, also from Pakistan. The now extinct whale Ambulocetus natans (”the walking whale that swam”) lived in the Tethys Sea 49 million years ago. It lived around 3 million years after Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good portion of the hind legs. The legs were strong and ended in long feet very much like those of a modern pinniped. The legs were certainly functional both on land and at sea. The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans. The structure of the backbone shows, however, that Ambulocetus swam like modern whales by moving the rear portion of its body up and down, even though a fluke was missing. The large hind legs were used for propulsion in water. On land, where it probably bred and gave birth, Ambulocetus may have moved around very much like a modern sea lion. It was undoubtedly a whale that linked life on land with life at sea.

Kết quả (Việt) 1:

Một khám phá lớn đã được thực hiện ở Ai cập vào năm 1989. Một số bộ xương của một đầu voi, Basilosaurus, đã được tìm thấy trong các trầm tích còn lại của biển Tethys và bây giờ tiếp xúc trong sa mạc Sahara. Cá voi này sống khoảng 40 triệu năm trước, 12 triệu năm sau khi Pakicetus. Nhiều bộ xương không đầy đủ đã được tìm thấy, nhưng họ bao gồm, lần đầu tiên trong một archaeocyte, một chân thô kịch hoàn chỉnh là một tính năng một chân với 3 ngón nhỏ. Như vậy chân đã có quá nhỏ để có hỗ trợ Basilosaurus 50-chân dài trên mặt đất. Basilosaurus chắc chắn là một con cá voi biển hoàn toàn có thể nonfunctional, hoặc dạng dấu vết dài, hind chân.An even more exciting find was reported in 1994, also from Pakistan. The now extinct whale Ambulocetus natans (”the walking whale that swam”) lived in the Tethys Sea 49 million years ago. It lived around 3 million years after Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good portion of the hind legs. The legs were strong and ended in long feet very much like those of a modern pinniped. The legs were certainly functional both on land and at sea. The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans. The structure of the backbone shows, however, that Ambulocetus swam like modern whales by moving the rear portion of its body up and down, even though a fluke was missing. The large hind legs were used for propulsion in water. On land, where it probably bred and gave birth, Ambulocetus may have moved around very much like a modern sea lion. It was undoubtedly a whale that linked life on land with life at sea.