The name Protochordates literally means 'the first chordates.' The chordates include fish, amphibians, reptiles, birds and mammals. The protochordates fall into two broad groups or subphyla - the Urochordata and the Cephalochordata. Urochordata The urochordata includes the group known as the tunicates - animals whose free-swimming larvae have a notochord* and a nerve chord. The adults are sessile - that is to say they are anchored to one place on the Reef. CephalochordataCephalochordates, or lancelets, are fish-like animals that have a notochord and nerve chord along the entire length of their bodies and which persist all their lives. * A notochord is a an elongated cellular chord enclosed in a sheath, that forms the primitive skeleton of chordate embryos (including humans) and adult cephalochordates. The name Protochordates literally means 'the first chordates.' The chordates include fish, amphibians, reptiles, birds and mammals. The protochordates fall into two broad groups or subphyla - the Urochordata and the Cephalochordata. Urochordata The urochordata includes the group known as the tunicates - animals whose free-swimming larvae have a notochord* and a nerve chord. The adults are sessile - that is to say they are anchored to one place on the Reef. Cephalochordata Cephalochordates, or lancelets, are fish-like animals that have a notochord and nerve chord along the entire length of their bodies and which persist all their lives. * A notochord is a an elongated cellular chord enclosed in a sheath, that forms the primitive skeleton of chordate embryos (including humans) and adult cephalochordates.
It has no significance at all, it is redundant.
Significance is a relative term. 264 is significant in comparison with 0.264 but not in comparisons to 264,000,000,000. Significance is a relative term. 264 is significant in comparison with 0.264 but not in comparisons to 264,000,000,000. Significance is a relative term. 264 is significant in comparison with 0.264 but not in comparisons to 264,000,000,000. Significance is a relative term. 264 is significant in comparison with 0.264 but not in comparisons to 264,000,000,000.
oldest male in the family
it meaNs to love
They have no significance.
Vetebrates and protochordates.
by there skin
any member of either of two invertebrate subphyla of the phylum Chordata: the Tunicata (sea squirts, salps, etc.) and the Cephalochordata (amphioxus). Like the remaining subphylum of the chordates, the Vertebrata, the protochordates have a hollow dorsal nerve cord, gill slits, and a stiff supporting rod, the notochord, the forerunner of the backbone. The protochordates differ chiefly from the vertebrates in not having a backbone. Recent protochordates are thought to have evolved from the same ancestral stock as that which gave rise to the vertebrates.
the did not evlove from that. they evloved from something else. once i find out i will put it out here.
Protochordates are important to scientists because they provide critical insights into the evolutionary transition from invertebrates to vertebrates. As the closest living relatives of vertebrates, they help researchers understand the origins of key vertebrate features, such as the notochord and dorsal nerve cord. Studying protochordates also sheds light on developmental processes and genetic mechanisms that are foundational to vertebrate biology. Additionally, they serve as model organisms for evolutionary and ecological studies.
Cephalochordates e.g. Amphioxus ,; tunicates , acorn worms etc. are nonvertebrate chordates , they are collctively called protochordates .
The endostyle is a crucial structure in certain chordates, particularly in protochordates like tunicates and amphioxus. It plays a key role in filter feeding by secreting mucus that traps food particles from the water, facilitating their movement toward the digestive tract. Additionally, the endostyle is considered an evolutionary precursor to the thyroid gland in vertebrates, highlighting its significance in the study of evolutionary biology and the development of endocrine systems.
Steven Andrew Torrence has written: 'Ascidian larval nervous system' -- subject(s): Protochordates, Sea squirts, Nervous system, Larvae
Protochordates, such as tunicates and amphioxus, use filter feeding to obtain food. Water is drawn into the mouth, passed through a sieve-like structure called the pharyngeal slits, and filtered to remove food particles. Cilia on the pharyngeal slits create a current to help move the water through the system.
Hermann Solms-Laubach has written: 'Die Corallinenalgen des golfes von Neapel und der angrenzenden meeres-abschnitte' -- subject(s): Algae, Coralline algae, Protochordates
no significance
The adjective of significance is significant.The adverb of significance is significantly.