tetrapod

American  

[te-truh-pod] / ˈtɛ trəˌpɒd /

noun

1. any vertebrate having four limbs or, as in the snake and whale, having had four-limbed ancestors.

2. an object, as a caltrop, having four projections radiating from one central node, with each forming an angle of 120° with any other, so that no matter how the object is placed on a relatively flat surface, three of the projections will form a supporting tripod and the fourth will point directly upward.

---

adjective

1. having four limbs or descended from four-limbed ancestors.

tetrapod British  

/ ˈtɛtrəˌpɒd /

noun

1. any vertebrate that has four limbs

2. Also called: caltrop.  a device consisting of four arms radiating from a central point, each at about 109° to the others, so that regardless of its position on a surface, three arms form a supporting tripod and the fourth is vertical

3. engineering a very large cast concrete structure of a similar shape piled in large numbers round breakwaters and sea defence systems to dissipate the energy of the waves

---

tetrapod Scientific  

/ tĕt′rə-pŏd′ /

1. Having four feet, legs, or leglike appendages.

2. Any of various mostly terrestrial vertebrates that breathe air with lungs. Most tetrapods have two pairs of limbs, though some, such as whales and snakes, have lost one or both pairs. Tetrapods include the amphibians, reptiles, birds, mammals, and various extinct groups, and evolved from lobe-finned fish during the late Devonian Period. Tetrapods are classified according to the structure of their skull into anapsids, diapsids, and synapsids.

---

Etymology

Origin of tetrapod

1820–30; < New Latin tetrapodus < Greek tetrapod- (stem of tetrápous ) four-footed. ( tetra-, -pod ) + New Latin -us adj. suffix

Example Sentences

The research team found that similar to the tetrapod and lobe-finned fish Aqp10s, Aqp10.1 in ray-finned fishes also transport water, glycerol, urea, and boric acid.

From Science Daily • Dec. 21, 2023

“Any new fossil that can help us understand what’s happening during the early stages of the evolution of the tetrapod body plan is incredibly important because we have such few fossils that document this period.”

From New York Times • Jul. 20, 2022

Previous research had shown that HoxD13 is active in the developing tetrapod limb when the wrists and digits form.

From Scientific American • Jun. 17, 2020

Like other similar fish, Elpistostege’s fin also has the precursors of tetrapod limb bones including the upper arm, forearm and wrist.

From Reuters • Mar. 19, 2020

Contributions to the question of the origin of the tetrapod limb.

From The Ancestry of Modern Amphibia: A Review of the Evidence by Eaton, Theodore H. (Theodore Hildreth)