Agnatha - Wikipedia
Agnatha (/ ˈ æ ɡ n ə θ ə, æ ɡ ˈ n eɪ θ ə /; [3] from Ancient Greek ἀ-(a-) 'without' and γνάθος (gnáthos) 'jaws') is a paraphyletic infraphylum [4] of non-gnathostome vertebrates, or jawless fish, in the phylum Chordata, subphylum Vertebrata, consisting of both living (cyclostomes) and extinct (conodonts, anaspids, and ...
Jawless Fish - Characteristics And Examples - AnimalWised
2019年9月2日 · Agnatha or jawless fish can be found in waters all over the world, and they share few characteristics with other marine mammals. But, what is a jawless fish? Keep reading here to find out! In this AnimalWised article we’ll be discussing the most common characteristics and examples of agnatha, images included.
agnathan - Encyclopedia Britannica
agnathan, (superclass Agnatha), any member of the group of primitive jawless fishes that includes the lampreys (order Petromyzoniformes), hagfishes (order Myxiniformes), and several extinct groups.
Jawless Vertebrates - Digital Atlas of Ancient Life
2020年5月29日 · The vast majority of jawless vertebrate diversity (mostly represented by ostracoderm fishes and conodonts) is now extinct, but one clade—the eel-shaped cyclostomes (hagfish and lampreys)—survive to the present day. Simplified overview of vertebrate phylogeny.
Jawless Fish - Fish & Fishing (U.S. National Park Service)
2017年5月8日 · Jawless fish are the most primitive fishes living today. Jawless fish: Lack jaws. Feed by suction with the help of a round muscular mouth and rows of teeth. Have cylindrical and long bodies. Do not have paired fins and scales like most fish. There are two categories of jawless fish: hagfish and lampreys. Hagfish. Hagfish usually feed on dead or ...
Agnathan - Evolution, Classification, Jawless | Britannica
Agnathan - Evolution, Classification, Jawless: Superclass Agnatha have fossils dating from the Ordovician Period, and are distinguishable from the other craniates by their lack of jaws. Living orders are Petromyzontiformes (lampreys) and Myxiniformes (hagfishes).
Agnatha - Characteristics, Classification, Morphology, …
2024年4月12日 · The Agnatha, meaning “without jaws,” is a superclass of jawless fish within the phylum Chordata and subphylum Vertebrata. It encompasses both living species, known as cyclostomes, and extinct species like conodonts and ostracoderms.
Jawless Fishes | Biology for Majors II - Lumen Learning
Jawless fishes (Agnatha) are craniates representing an ancient vertebrate lineage that arose over 550 million years ago. In the past, hagfishes and lampreys were sometimes recognized as separate clades within the Agnatha, primarily because lampreys were regarded as true vertebrates, whereas hagfishes were not.
Jawless Fish - Examples, Characteristics, Classification & Picture
2024年7月9日 · Jawless fish, belonging to the infraphylum Agnatha, are unique among vertebrates due to their lack of jaws. They possess long, cylindrical bodies devoid of paired fins and scales and feature seven or more paired gill pouches.
Superclass Agnatha: Jawless Fishes | Fishes | The Diversity of …
Living jawless fishes are represented by approximately 84 species divided between two classes: Myxini (hagfishes) with about 43 species and Cephalaspidomorphi (lampreys) with 41 species (Figures 26-3 and 26-4).