Scientists studied a fossil (see image) discovered in central China for 10 years. They recently announced their findings. The fossil belongs to an animal that walked our planet around 55 million years ago. The animal’s species has been given the name Archicebus achilles. It was approximately the size of a mouse with a weight of about 25 grams (1 ounce). It had feet like a monkey, two small eyes, and a long tail. Archicebus was a primate, and this is the oldest primate fossil discovered so far. It is 7 million years older than the previously oldest known primate fossil.
When Archicebus roamed Earth, our planet was much warmer and was covered with forests. The continents looked very different from how they look today (see image).
It is believed that our planet came into existence around 4.5 billion years ago. The first living things (single-celled organisms) came into existence around 3.5 billion years ago. The first multi-celled animals showed up approximately 600 million years ago. Dinosaurs came into existence around 240 million years ago, and they all died around 65 million years ago. Humans came into existence just 0.2 million years ago. (We humans have been on the planet for a very short time – if Earth was a day old, we humans arrived less than four seconds ago.) It is unclear as to exactly when the first primates showed up on Earth, but it is believed to be soon after the extinction of the dinosaurs.
Primates are mammals with some common features such as a large brain-to-body ratio, eyes that face forward, and a shorter snout since primates rely more on their vision than sense of smell. Primates are the only mammals with flat nails. Lemurs, tarsiers, monkeys, apes, and humans are some examples of primates.
Some time after primates appeared on Earth, they split into various groups. The tarsiers split from the anthropoids (that’s made up of humans, apes, and monkeys) at some point. The characteristics of Archicebus place it in the tarsiers’ group. However, it has some anthropoid-like features and that places Archicebus close to the timeline when the tarsiers and anthropoids split up. Tarsiers are found in southeast Asia. They are small animals with large eyes and long tails, fingers, and toes. Here is a video showing a tarsier.
Here is Earth’s timeline from National Geographic.
Did you know?
The pygmy mouse lemur from Madagascar is the smallest living primate today.
Did you know?
Mount Everest, the tallest mountain in the world today, was created when India moved northward and merged with part of Asia. Mount Everest was not the tallest peak when the Archicebus achilles whose fossil was discovered walked on our planet. Here is a timeline of how Mount Everest was created. Here is a video showing how Mount Everest was created.
Image Credits: Chinese Academy of Science and NI Xijun for Archicebus achilles’ images, Dr Ron Blakey, NAU Geology for our continent’s image
Sources: http://english.cas.cn/Ne/CASE/201306/t20130606_102985.shtml, http://www.britannica.com/