Echinoderms: Evolution And Lifestyle
These animals belong to Echinodermata phylum and its characteristics include a spiny covering. The animals are adequately represented across many groups. They have existed since the Cambrian period, which is over 500 million years ago.
The animals have a rich history that connects all the way back to the Cambrian period. The animals have various species spread across a wide area. As such, there is a lot to learn about these species, as there are many across the board.
Over the years, scientists have written various papers on echinoderms and their evolution. This provides insights into the lifestyle of the animals and how they have evolved over the years.
These animals fall under 21 separations. They have been categorised differently based on their structures. The animals have various structures ranging across different species. That is, what you’ll find in the structure of a species is different from what you’ll find with another.
Scientists have realised that there are over 13 000 species of echinoderms. This makes the group a very vast one among invertebrates. They are also found across various places in the world. They have a wide habitat range, meaning that they can survive in any places conveniently. This is unlike some other animals that find it hard surviving under certain conditions even in the sea.
The size range for these animals is generally on the small side. Most of the echinoderms that can be found have a size within the 10cm range. However, while many of them might have small sizes, there are some that are larger in sizes.
A good number of those in this category are now extinct. Some of these extinct ones have stems that were longer than 20 metres. The diversity of these animals also extend to their form, as there are different shapes of echinoderms. While all echinoderms have a five-part skeletal framework, most are diverse based on their outlook.
While some have the flower-like structure, some others have the structure of a worm, while some others might appear like sea cucumbers. They can also come as a star with extended arms. This goes to show the level of diversity you’ll find with echinoderms, as their shapes aren’t boxed into a particular type.
Echinoderms are known for their impressive colours. They come in different colours such as red and orange. This makes them bright in the sea. Those found in the tropical area are generally brown or dark.
However, those that have not received much sunlight are not as bright in colour as those that have. Since the species are abundant, it is natural to find echinoderms across various seas. The only place where they’re limited is the Arctic.
In Antarctica, many of the echinoderms are spread across quite evenly. One thing to note about echinoderms is their depth range. Most of the species have a limited range such that they mostly are found in the seashore. The ones that get into the sea do not go far in.