Laugiidae Explained

Laugiidae is an extinct family of prehistoric marine coelacanths which lived during the Triassic and Jurassic periods.^[1] Their fossils have been found in Canada, Germany and Greenland.^[2]

They are notable for the extreme temporal disjunction seen between genera; two genera, Laugia and Belemnocerca, are known from the Early Triassic, and another (Coccoderma) is known from the Late Jurassic, leaving a ghost lineage spanning 100 million years between these two time periods. The presence of Coccoderma in the Late Jurassic makes Laugiidae the latest surviving non-latimerioid coelacanth lineage; almost all other non-latimerioid coelacanths were extinct by the Carnian stage of the Late Triassic, leaving only the latimerioids (Latimeriidae and Mawsoniidae) as the dominant coelacanth groups. It has been estimated that the laugiids diverged from the latimerioids & allied taxa (such as the Whiteiidae) during the Early Permian.^[3]

Included genera

• Belemnocerca Wendruff & Wilson, 2012
• Coccoderma Quenstdedt, 1858
• Laugia Stensiö, 1932 (type)

A potential indeterminate genus is known from the Late Triassic of China.^{[4] [5]} The Carboniferous genus Synaptotylus was previously included in this family, but is no longer thought to be a member.^[6]

Some studies indicate that the genus Piveteauia, known from the Early Triassic of Madagascar and previously considered a member of the Whiteiidae, may actually be a laugiid.

Further reading

• Peter L. Forey: History of the Coelacanth Fishes. Springer Verlag GmbH,
• Karl Albert Frickhinger: Fossilien Atlas Fische, Mergus-Verlag, Melle, 1999,

Notes and References

1. Web site: PBDB Taxon . 2024-05-22 . paleobiodb.org.
2. Wendruff . A.J. . Wilson . M.V. . 2013 . New Early Triassic coelacanth in the family Laugiidae (Sarcopterygii: Actinistia) from the Sulphur Mountain Formation near Wapiti Lake, British Columbia, Canada . Canadian Journal of Earth Sciences . 50 . 9 . 904–910 . 10.1139/cjes-2013-0010. 2013CaJES..50..904W .
3. Toriño . Pablo . Soto . Matías . Perea . Daniel . 2021-12-02 . A comprehensive phylogenetic analysis of coelacanth fishes (Sarcopterygii, Actinistia) with comments on the composition of the Mawsoniidae and Latimeriidae: evaluating old and new methodological challenges and constraints . Historical Biology . en . 33 . 12 . 3423–3443 . 10.1080/08912963.2020.1867982 . 0891-2963.
4. Guan-bang1 . Liu . Zhao-xin2 . Zhu . Xing-Liang2 . Zhang . Fang2 . Ai . 1999-12-20 . A COELACANTHID FOSSIL FROM HUACHI AREA, GANSU PROVINCE . Geological Journal of China Universities . en . 5 . 4 . 474 . 1006-7493.
5. Tong . Jinnan . Zhou . Xiugao . Erwin . Douglas H. . Zuo . Jingxun . Zhao . Laishi . 2006 . Fossil Fishes from the Lower Triassic of Majiashan, Chaohu, Anhui Province, China . Journal of Paleontology . 80 . 1 . 146–161 . 0022-3360.
6. Cloutier . Richard . 1996 . Morphology, characters, and the interrelationships of basal sarcopterygians . Interrelationships of Fishes.