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Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened).
[5] Declines in amphibian populations were first widely recognized in the late 1980s [citation needed], when a large gathering of herpetologists reported noticing declines in populations in amphibians across the globe. [6] Among these species, the golden toad (Bufo periglenes) endemic to Monteverde, Costa Rica, featured prominently.
Mass extinctions are characterized by the loss of at least 75% of species within a geologically short period of time (i.e., less than 2 million years). [18] [51] The Holocene extinction is also known as the "sixth extinction", as it is possibly the sixth mass extinction event, after the Ordovician–Silurian extinction events, the Late Devonian extinction, the Permian–Triassic extinction ...
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 ostracoderms, among others).
World fisheries and aquaculture production of aquatic animals by area and relative shares of world production, 2022. Total fish production in 2016 reached an all-time high of 171 million tonnes, of which 88% was utilized for direct human consumption, resulting in a record-high per capita consumption of 20.3 kg (45 lb). [12]
The smallest amphibian (and vertebrate) in the world is a frog from New Guinea (Paedophryne amauensis) with a length of just 7.7 mm (0.30 in). The largest living amphibian is the 1.8 m (5 ft 11 in) South China giant salamander ( Andrias sligoi ), but this is dwarfed by prehistoric temnospondyls such as Mastodonsaurus which could reach up to 6 m ...
The world ocean covers an area of 3.618 × 10 8 km 2 with a mean depth of 3682 m, resulting in an estimated volume of 1.332 × 10 9 km 3. [17] If all of Earth's crustal surface was at the same elevation as a smooth sphere, the depth of the resulting world ocean would be about 2.7 kilometres (1.7 mi).
About 11 distantly related genera of fish are considered amphibious. This suggests that many fish genera independently evolved amphibious traits, a process known as convergent evolution. These fish use a range of methods for land movement, such as lateral undulation, tripod-like walking (using paired fins and tail), and jumping.