Lancelet - definition of lancelet by The Free Dictionary.

Lancelet definition is - any of a subphylum (Cephalochordata) of small translucent marine primitive chordate animals that are fishlike in appearance and usually live partially buried on the ocean floor —called also amphioxus.

The lancelet, particularly of the genus Branchiostoma. Definition from Wiktionary, the free dictionary.

AMPHIOXUS, or Lancelet, the name of small, fish-like, marine creatures, forming the class Cephalochorda, of the phylum Vertebrata. Lancelets are found in brackish or salt water, generally near the coast, and have been referred to several genera and many species. They were first discovered by P. S. Pallas in 1778, who took them to be slugs and described them under the name Limax lanceolatus.

The lancelets, or Cephalochordata, are a group of primitive chordates which were formerly called Amphioxus.It includes Pikaia. Lancelets are the modern survivors of an ancient chordate lineage, with a fossil record dating back to the Cambrian period. The lancelets are usually said to be the sister group of the craniates.They are a small group of about 30 species in two genera.

Branchiostoma lanceolatum (European lancelet, or Mediterranean amphioxus) is a lancelet in the subphylum Cephalochordata. It is a marine invertebrate with a notochord but no backbone and is used as a model organism to study the evolutionary development of vertebrates. 2 Distribution and habitat. Anatomical diagram of Branchiostoma lanceolatum.

Amphioxus, echinoderms, and amphibians. Gastrulation does not always proceed exactly as described above. In the course of evolution, certain animal groups have modified this critical stage of embryonic development, and these modifications have undoubtedly contributed to the successful continuation of species.In the primitive fishlike chordate amphioxus, for example, the invaginating blastoderm.

Amphioxus. STUDY. Flashcards. Learn. Write. Spell. Test. PLAY. Match. Gravity. Created by. Chewbilicious. Terms in this set (37) Dorsal Fin. Extends the entire length of the body. A short projection from the dorsal mid-line region that is supported by the gelatinous fin rays). Caudal Fin. An expanded continuation of the median dorsal fin at the posterior end of the body. A short projection.

The lancelet is a filter feeder and has several organs to aid in consumption and digestion. CreationWiki - Recent changes (en) Amphioxus, also known as the lancelet, diverged from vertebrates more than 500 million years ago, and is often studied by researchers hoping to learn more about the early history of vertebrates. NPR Topics: News. The lancelet is a filter feeder and has several organs.

Lancelet (Amphioxus) Pharynx. The lancelet, or amphioxus, is a diminutive marine organism that is similar in appearance to an eel. Members of the phylum Chordata, lancelets do not often reach lengths of more than three inches and lack eyes, as well as a distinct heads. Though capable of swimming, lancelets typically remain buried in the sand or mud that lines the ocean floors. To feed, they.

If, as in amphioxus, the atrial surface of the vertebrate ancestor rather than the gill bars themselves were the respiratory exchanger, then a stepwise modification of the gill structures can be envisioned. The ventilatory motor could be changed from cilia to a velum, and expanded surfaces could develop in the gills while leaving the filter-feeding mechanism intact, as in the ammocetes larva.

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