Coelacanth
Coelacanth
Fossil range: Devonian–Cretaceous (but extant)
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O
S
D
C
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Pg
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Latimeria chalumnae
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Sarcopterygii
Subclass:
Actinistia
Infraclass:
Coelacanthimorpha
Order:
Coelacanthiformes
Berg, 1937
Families
See text.
Coelacanth (pronounced /ˈsiːləkænθ/, adaptation of
Modern Latin Cœlacanthus: cœl-us + acanth-us from
Greek κοῖλ-ος [hollow] + ἄκανθ-α [spine]) is the common
name for an order of fish that includes the oldest living
lineage of gnathostomata known to date. The coel-
acanths, which are related to lungfishes and tetrapods,
were believed to have been extinct since the end of the
Cretaceous period, until the first Latimeria specimen was
found off the east coast of South Africa, off the
Chalumna River in 1938. They are, therefore, a Lazarus
taxon. Since 1938, Latimeria chalumnae have been found
in the Comoros, Kenya, Tanzania, Mozambique, Mada-
gascar, and in iSimangaliso Wetland Park, Kwazulu-Natal
in South Africa. The second extant species, L. menadoen-
sis, was described from Sulawesi, Indonesia in 1999.[1][2]
The coelacanth has no real commercial value, apart from
being coveted by museums and private collectors. As a
food fish the coelacanth is almost worthless as its tissues
exude oils even when dead, imparting the tough flesh
with a foul flavour.[3]
Natural history
They first appeared in the fossil record in the Middle
Devonian.[4] Prehistoric species of coelacanth lived in
many bodies of water in Late Paleozoic and Mesozoic
times.
Coelacanths are lobe-finned fish with the pectoral
and anal fins on fleshy stalks supported by bones, and
the tail or caudal fin diphycercal (divided into three
lobes), the middle one of which also includes a continu-
ation of the notochord. Coelacanths have modified cos-
moid scales, which are thinner than true cosmoid scales.
Coelacanths also have a special electroreceptive device
called a rostral organ in the front of the skull, which
probably helps in prey detection. The small device