The chordata phylum is a large and diverse group, including animals with backbones present in the Cambrian period, which are classified under this same word. The chordates are made up of subphyla Urochordata (tunicates), Cephalochordata (lancelets) and Vertebrata.
My conclusion is that since the chordata phylum predates the Cambrian period, and vertebrates within this phylum did not exist until after the Cambrian period, then chordata did not evolve from Urochordata or Cephalochordata.
As for chordata coming from the word "chord" meaning string or tendon, this is false.
The word chordata is derived from the Latin chorda, meaning stringed instrument. This is likely because some species of this phylum use internal skeletons to help them move and live.
In order to understand the etymology of chordata, we must first investigate what it is. Chordata are a sub-classification of invertebrated animals with a notochord during embryonic development that eventually becomes the spine and contributes to their dorsal support structure. The sub-class also includes vertebrates, which branch out into fish, amphibians, reptiles, birds and mammals.
The real question is, are chordata really that important? It seems to me that the classification is rather arbitrary and doesn't help us understand anything about the origin of chordata. I think it's just another system designed to make things easier for researchers like yourself, so you can easily divide up information.
As you know, chordata are invertebrates. This means they don't have a skeleton on the outside of their bodies to protect them and give them structure.
Instead, chordata have an internal skeleton which is made of cartilage. This makes them very flexible and adaptable to their environment.
However, it is the chordata's structure which makes them a sub-classification rather than a separate type of animal. It seems that chordata themselves have no real importance and are just there to make up numbers.
I would suggest that chordata are more of a historical classification rather than a functional one. We could easily change the name to something better, but I don't think it's worth bothering about.
It is of course obvious that chordata are the species which have a cord. What is less obvious, however, as you've probably already realized, is what exactly this cord might be.
I think we need to make a distinction between the literal cord, and the figurative cords that people in general might have. The literal cord seems to be a part of chordata anatomy, but what about the figurative cords? I'm not entirely sure.
Chordata are a phylum of animals. This means that they share some common characteristics, which can be described by a short string of words - in this case: cord-bearing-animal. In fact, chordata are part of the subphylum Vertebrata (which literally means 'chorded animal'). The name vertebrata comes from Latin via Old French (there was no Latin word for it). It is not entirely clear what the earliest Indo-European root really was.
The word chordata is itself a blend of two Latin words, chorda (chord) and -ata (like mamillata or digitata). In this case the suffix -ata means 'having', so a literal translation of chordata would be 'corded ones'.
The word chorda is from a Greek root, khorassein (meaning 'to fasten' or 'to bind'). It refers to the notochord, which vertebrates possess. The notochord is an embryonic structure that disappears during development.
It is interesting to note that the word chorda (in its various forms) means 'string' in several languages, including Spanish and German. This may be a coincidence, but it does suggest that there might be some connection between the literal cord of chordata and their figurative cords.
The word "chordata" is a group of animals that have tendons or chords in their body. The chordates are not divided, but they grow and change just like other organisms.
Most chordates are able to move through their environment and have a nervous system that can detect information from the outside world.
The first chordate that existed was a fish called the "Cephalaspis". It lived about 410 million years ago.
The Cephalaspis was a very small fish that lived in the shallow water of the Cambrian sea and it had an internal skeleton. It could also move around on its fins.
The Cephalaspis is not considered to be a direct ancestor of humans, but it was the first chordate.
The first chordate that can be considered an ancestor of humans is the "Ventastega". It was about 3 feet long and lived approximately 385 million years ago.
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