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The largest living amphibian is the 1.8 m (5 ft 11 in) Chinese giant salamander (Andrias davidianus) [41] but this is a great deal smaller than the largest amphibian that ever existed—the extinct 9 m (30 ft) Prionosuchus, a crocodile-like temnospondyl dating to 270 million years ago from the middle Permian of Brazil. [42]
The etymology of the word "morphology" is from the Ancient Greek μορφή (morphḗ), meaning "form", and λόγος (lógos), meaning "word, study, research". [2] [3]While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist ...
In fish and aquatic amphibians, it is a thin mucus layer that is constantly being replaced. In terrestrial vertebrates, it is the stratum corneum (dead keratinized cells). The epidermis is, to some degree, glandular in all vertebrates, but more so in fish and amphibians. Multicellular epidermal glands penetrate the dermis, where they are ...
Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia.In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals).
Aristotle affirmed that every living being consists of two intrinsic parts: [4] Primary matter (οὐσία) Substantial form (εἶδος) He used those principles to study the primordial elements of the nature of which the bodies of animals are composed and the intrinsic conditions that make bodies become what they are.
Common organ system designations in plants include the differentiation of shoot and root. All parts of the plant above ground (in non-epiphytes), including the functionally distinct leaf and flower organs, may be classified together as the shoot organ system. [12] The vegetative organs are essential for maintaining the life of a plant.
The dorsal part of the body wall is a mantle (or pallium) which secretes calcareous spicules, plates or shells. It overlaps the body with enough spare room to form a mantle cavity. The anus and genitals open into the mantle cavity. There are paired nerve cords. [18] Other characteristics that commonly appear in textbooks have significant ...
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. Originally, it included plant morphology , the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.