Agnatha - Wikipedia
网页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 ...
無頜總綱 - 维基百科，自由的百科全书
网页無頜總綱. 无颌总纲[註 1] （页面存档备份，存于 互联网档案馆）（學名： Agnatha）是 脊索动物門 下的一个总纲。. 该纲动物是无成对偶肢和上下颌的原始脊椎动物。. 本纲动物生活于淡水和海水中，有些种类会 洄游。.
agnathan - Encyclopedia Britannica
网页2024年9月20日 · 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. Hagfishes are minor pests of commercial food fisheries of the North Atlantic, but lampreys, because of …
无颌类 - 百度百科
网页无颌类（Agnatha）指的是脊索动物门，脊椎动物亚门，无颌纲。 与“有颌类”相对，脊椎动物的两大类之一，属较原始的类别，是迄今为止最原始的水生鱼形脊椎动物。
Agnathan - Evolution, Classification, Jawless | Britannica
网页2024年9月20日 · 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 …
Agnatha - Characteristics, Classification, Morphology, …
网页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. These jawless fish are closely related to vertebrates with jaws, known as gnathostomes.
29.2A: Agnathans- Jawless Fishes - Biology LibreTexts
网页2023年10月31日 · Jawless fishes or agnathans are craniates that represent an ancient vertebrate lineage that arose over one half-billion years ago. “Gnathos” is Greek for “jaw” and the prefix “a” means “without,” so agnathans are “without jaws. ” Most agnathans are now extinct, but two branches still exist today: hagfishes and lampreys.
Jawless Fishes | Biology for Majors II - Lumen Learning
网页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.
无颌总纲 - 百度百科
网页无颌总纲(Agnatha)是脊索动物门下的一个总纲。 该纲动物是无成对偶肢和上下颌的低等脊椎动物。 本纲动物生活于淡水和海水中，有些种类具有回游。
Agnatha - New World Encyclopedia
网页Agnatha (Greek, "no jaws"), often considered a superclass within the subphylum Vertebrata, comprises the jawless fish—the oldest known vertebrates. The two extant groups of jawless fish (sometimes called cyclostomes) are the lampreys and the hagfish .