- 10 Steps of Animal Evolution, From Fish to Primates
- How Vertebrates Left the Water - Michel Laurin - Google книги
- See a Problem?
- Amphibians - Slimy Is Good
The search for an answer took her to Greenland, where she found one of the earliest known tetrapods, called Acanthostega.
10 Steps of Animal Evolution, From Fish to Primates
With its fishlike tail and gills, it was certainly adapted to an aquatic environment, but its paddle-shaped fins end in tiny fingers. Vertebrates , it turns out, grew fingers before they left the sea. From Evolution: "Great Transformations". All rights reserved.
View in: QuickTime RealPlayer. Fish with Fingers: One of the most important milestones in the evolution of life began some million years ago, when the first animals made their way from water onto land. At that time, known as the Devonian period, the world was changing dramatically: complex plant ecosystems formed on land, the first woody plants appeared, and the water's edge was becoming a new kind of environment.
- About this book.
- Amphibians - Slimy Is Good.
- Redemption: Incubus.
The move to land was a very gradual process, and the evolution of limbs wasn't a simple adaptation resulting from animals crawling onto the shore and never looking back. In fact, the new picture of this transition shows that most of the changes needed for life on dry land happened in creatures that were still living in the water.
How Vertebrates Left the Water - Michel Laurin - Google книги
Some fishlike vertebrates had already begun to evolve limbs by around million years ago: They were called "lobe-fins," with fins that looked like fleshy paddles, and they had lungs as well as gills. The transition from these lobe-fins to the earliest tetrapods -- four-legged animals that walked on land -- has long been of intense interest to biologists.
Many of the most telling fossils have been dug up in Greenland in the latter part of the 20th century, particularly in the past 15 years.
One of the first vertebrates that may have ventured onto land, whose remains date from about million years ago, is called Ichthyostega. Although fishlike in many ways, it had robust bony legs, arms, and digits. Unfortunately, they live in areas man may not be, so we will never know.
Salamanders Salamanders are like frogs, but their body shape is more like a lizard.
See a Problem?
They are longer and have shorter legs. Often their bodies lay flat on the ground because their limbs legs are attached on the side of their bodies, not underneath as in mammals. You will often find salamanders around ponds and other small bodies of fresh water. Caecilians Caecilians are wild. They look kind of like snakes but are actually amphibians that found an advantage in not having legs or feet.
- How Vertebrates Left the Water | Systematic Biology | Oxford Academic!
- Training A Puppy.
- How Vertebrates Left the Water | NHBS Academic & Professional Books?
- The Secret at Solaire (Nancy Drew Book 111).
- How Vertebrates Left the Water;
- What is Kobo Super Points?.
- An Introduction to Trading in the Financial Markets: Market Basics!
You might be thinking that doesn't sound like an advantage. You need to remember that when amphibians were the first creatures on land, there were no snakes. There was an entire ecological niche to be filled. Some amphibians evolved to slither along the ground and eat insects and worms. When you have a body like a snake you can get into tight spaces and find tasty insects for your lunch.
Those slithering amphibians filled a specialized ecological niche that snakes filled millions of years later. Useful Reference Links.
Amphibians - Slimy Is Good
See the full list of biology topics at the site map! Current Page: Biology4Kids.
They are paid advertisements and neither partners nor recommended web sites.