![Picture](/uploads/6/3/4/4/63446829/5275323.jpg?341)
Sinonyx
The Sinonyx was a 5 feet, wolf-sized hyena-like, land-dwelling mammal with hoofs. It lived around around 56 MYA, and it started to enter the sea for the rich food sources of the ocean. The Sinonyx has dental and facial characteristics like living whales and dolphins. This included an elongated muzzle (jaws, mouth and nose), like many fish-hunting whales and dolphins. It had 44 teeth, just like all primitive mammals, and they had different types of teeth. It had hooves, like a goat or cow.
![Picture](/uploads/6/3/4/4/63446829/178165.jpeg?557)
Rodohocetus
The Rodhocetus lived approximately 46 million years ago and had a powerful tail for swimming and a more flexible spine for tail movements. This is the earliest known mammal to swim mainly using its tail to move rather than its legs. It still appeared to have legs strong enough to move on land, but they were shorter, and not very useful. The nostrils had moved back along the snout to a point above the canine teeth – the first example of blowhole evolution. It was discovered in Egypt.
The Rodhocetus lived approximately 46 million years ago and had a powerful tail for swimming and a more flexible spine for tail movements. This is the earliest known mammal to swim mainly using its tail to move rather than its legs. It still appeared to have legs strong enough to move on land, but they were shorter, and not very useful. The nostrils had moved back along the snout to a point above the canine teeth – the first example of blowhole evolution. It was discovered in Egypt.
![Picture](/uploads/6/3/4/4/63446829/6363980.png?590)
Dorudon
The Dorudon lived approximately 40 MYA, at the same time as Basilosaurus, and it is the most likely ancestor to the modern whales. Dorudon was fully aquatic and lacked large enough limbs to move around on land. It was much smaller than Basilosaurus (approx. 15 ft.). It did not have the ability to use underwater sounds to locate objects (echolocation) as some modern whales can. Its fossilized remains were first found in present-day Egypt and Pakistan, but have since been found in the United States, New Zealand, and Western Sahara.
![Picture](/uploads/6/3/4/4/63446829/6545785.jpeg?428)
Basilosarus
Basilosarus was a very large, serpentine (snake-like) animal that was first thought to be the remains of a sea serpent. It was approximately 50-ft. long and lived approximately 35 – 45 MYA. It was very small around the hips, and had hind limb bones that were too small to bear its weight on land. The vertebral column shares characteristics of whales with tail flukes. The nostrils had fused into a large single blowhole that had moved further back on the head. Basilosaurus was first discovered in the United States, but has recently been discovered in Egypt and Jordan.
Basilosarus was a very large, serpentine (snake-like) animal that was first thought to be the remains of a sea serpent. It was approximately 50-ft. long and lived approximately 35 – 45 MYA. It was very small around the hips, and had hind limb bones that were too small to bear its weight on land. The vertebral column shares characteristics of whales with tail flukes. The nostrils had fused into a large single blowhole that had moved further back on the head. Basilosaurus was first discovered in the United States, but has recently been discovered in Egypt and Jordan.
![Picture](/uploads/6/3/4/4/63446829/2752769.jpg?435)
Ambolocetus
Ambolocetus is one of the best examples of an animal between whales and terrestrial (land) animals. It lacked a blowhole, but its skull and tooth structure were very similar to modern whales. Its spine moved up and down for swimming, like the modern whales do, but its four legs were still functional enough that it was probably able to walk on land in the same way sea lions do today. This amphibious animal lived about 47 MYA and it was first discovered in Pakistan and India.
Ambolocetus is one of the best examples of an animal between whales and terrestrial (land) animals. It lacked a blowhole, but its skull and tooth structure were very similar to modern whales. Its spine moved up and down for swimming, like the modern whales do, but its four legs were still functional enough that it was probably able to walk on land in the same way sea lions do today. This amphibious animal lived about 47 MYA and it was first discovered in Pakistan and India.
![Picture](/uploads/6/3/4/4/63446829/7858180_orig.gif)
Indohyus
The Indohyus was about a 12 to15 pound mammal that looked like a miniature deer. The Indohyus had heavy bones making it slow on land and easier prey for predators. In the water the same structural feature would help it stay on the bottom, where it could forage and hide. It has an unusual bone structure around the animal’s ear. It was a little bowl-shaped structure. The inside of that bone is very thick, the outside of the bone is very thin. Whales are the only mammal with this unique bone structure. It lived about 49 MYA and was first discovered in the Himalayan Mountains in Nepal.
The Indohyus was about a 12 to15 pound mammal that looked like a miniature deer. The Indohyus had heavy bones making it slow on land and easier prey for predators. In the water the same structural feature would help it stay on the bottom, where it could forage and hide. It has an unusual bone structure around the animal’s ear. It was a little bowl-shaped structure. The inside of that bone is very thick, the outside of the bone is very thin. Whales are the only mammal with this unique bone structure. It lived about 49 MYA and was first discovered in the Himalayan Mountains in Nepal.