Table of Contents
Why are echinoderms classified as Bilateria?
Echinoderms take many forms of symmetry. Pentameral symmetry is the major form and the other forms are derived from it. However, the ancestors of echinoderms, which originated from Cambrian period, were believed to be bilaterians. Overall, echinoderms are thought to have a bilateral developmental mechanism and process.
Which of the following groups of animals is echinoderms?
Echinoderms. Echinoderms are a phylum of marine invertebrates that include starfish, brittle stars, sea cucumbers, sea urchins, sand dollars, and crinoids. They are one of the most diverse groups of marine invertebrates and play important ecological roles from the near-shore environment to the deep seas. Dupont et al.
Which phylum is most closely related to echinoderms?
phylum Chordata
Echinoderms are the most closely related phylum to the phylum Chordata, which includes many complex organisms such as humans. Their shared common ancestor was likely a bilaterally symmetrical organism with a cephalized (centralized in a head region) nervous system.
What does Pentameral symmetry mean?
pentameral symmetry Five-sided symmetry, found in most members of the phylum Echinodermata. In some groups this symmetry has a bilateral symmetry superimposed on it. A Dictionary of Earth Sciences.
Is Bilateria a phylum?
The Bilateria /baɪləˈtɪəriə/ or bilaterians are animals with bilateral symmetry as an embryo, i.e. having a left and a right side that are mirror images of each other….Bilateria.
| Bilaterians Temporal range: Ediacaran–Present, | |
|---|---|
| Subkingdom: | Eumetazoa |
| Clade: | ParaHoxozoa |
| Clade: | Bilateria Hatschek, 1888 |
| Phyla |
Which 2 groups make up the Bilaterians?
The 2 groups of bilaterally symmetrical animals (the Bilateria)- protostomes and deuterostomes- differ in embryology.
Which one of the following is an Echinoderm?
Sea lily. Hint: Echinoderm is a member of the genus Echinodermata of marine animals. Adults are recognized by their radial symmetry (usually five points) and include starfish, sea urchins, sand dollars and sea cucumbers, as well as water lilies or “stone lilies”.
Which of the following are echinoderms?
Which of the following are echinoderms? Sea stars, sand dollars, and sea urchins.
Why are echinoderms and chordates grouped together?
Echinoderms and chordates are grouped together because they both are deuterostomes, or animals that grow radially, have a blastopore that develops…
How do echinoderms differ from the annelid mollusc arthropod group?
Mollusks are a separate phylum of animals. Although both phyla are made up of invertebrates, differences in their anatomy are why starfish are classified as echinoderms and not mollusks. Echinoderms have spiny skin and many physical attributes that are unique in the animal kingdom.
What does the word Pentameral mean?
adj. 1. consisting of or divided into five parts. 2. (of flowers) having five members in each whorl.
What group of animals that possess five fold symmetry?
Though Echinodermata is the only animal phylum to exhibit the five-fold symmetry, there are many interesting examples within. Sea lilies are an ancient group that has a feathery appearance, and is common in the fossil record.