Allenypterus, Ticinepomis, Undina, Foreyia, Coelcanthus, Ghuizhoucoelcanthus, Holopterygius, Hadronector, Revellatrix and Latimeria

Fish - Chordata

Basal Chordata

Chondrichthyes

Acipenseriformes

Placodermi

Siluriformes - Acanthodii

Amiiformes

Tetrapoda

Reptilia/Amniota

Lepidosauromorpha

Cephalerpeton clade

Captorhinidae

Milleretta Limnoscelis clade

Bolosaurus Diadectes clade

Turtle Pareiasaur clade

Fenestrasauria • Pterosauria

Protosquamata

Squamata

Archosauromorpha

Basal Archosauromorpha

Undina penicillata (Münster 1834, Jurassic, 155 mya, 20cm) is a small basal coelacanth with small lobes. The tooth row extends to mid-orbit.

Ticinepomis peyeri (Rieppel 1980, Cavin, Furrer and Obrist 2013, Middle Triassic, 18 cm long) nests basal to Guizhoucoelacanthus and Foreyia in the LRT. Note the convex rostral profile.

Guizhoucoelacanthus guanlingensis (Liu et al. 2006; Geng, Zhu and Jin 2009; 50cm in length; Middle Triassic, 225 mya) has a small orbit and large cheek bones. The caudal fin was larger, the other fins smaller.

Foreyia maxkuhni (Cavin et al 2017, PIMUZ A/I 4620, Middle Triassic) nests with coeval Guizhoucoelacanthus in the LRT, contra the original nesting. The shape is shorter both cranially and post-cranially. A sagittal crest is present. Note the small pectoral fins. Teeth are either absent or fused, as in Guizhoucoelacanthus.

Hadronector donbairdi (Lund and Lund 1984; 10cm long; Middle Carboniferous) is a small, early coelacanth without lobes.

Holopterygius nudus (Jessen 1973; Friedman and Coates 2006; Late Devonian <7cm) is a tiny coelacanth with a deep straight tail and no lobes, between Hadronector and Allenypterus. The authors presented a small maxilla, but did not mention it in their text. Here that element is a transverse palatine. Early Devonian Dialipina was not included in analysis.

Allenypterus montanus (Melton 1969; Lund and Lund 1984; 10cm long; Middle Carboniferous) is a small, early coelacanth with a distinct tear-drop shape. The dorsal fins and anal fins have internal lobes, so no external lobes.

Latimeria chalumnae (Smithi 1939) is the extant coelacanth, a slow-swimming deep-water fish. The fins arise from long lobes. The postorbital is large. The supratemporal is absent. The maxilla is fused to the jugal and lacrimal and maxillary teeth are absent.

Coelacanthus granulatus (Agassiz 1839; 70cm in length; Late Permian 250mya) was the first coelacanth described, about a century before Latimeria was discovered.

Rebellatrix divaricerca (Wendruff and Wilson 2012, Early Triassic, up to 1.1m) isthe fork-tailed coelacanth. Three specimens are known all incomplete. The holotype skull is disarticulated and stirred by currents or scavengers. Two overlapping pectoral fins appear to be preserved in the holotype rather than one anterior dorsal fin. Here Rebellatrix nests with Latimeria, the extant coelacanth.

Rebellatrix "is unique among coelacanths in its possession of a bifurcated caudal fin, reduced segmentation of fin rays, and fusion of caudal fin elements. The slender, fork-tailed body form suggests fast swming and an active lifestyle, unique among known fossil and extant coelacanths."

Agassiz L 1839. Recherches sur les poissons fossiles II. Petitpierre, Neuchâtel.

Brough J 1939. The Triassic fishes of Besano, Lombardy. London: British Museum (Natural History). 1–117.

Bürgin T 1992. Basal ray-finned fishes (Osteichthyes; Actinopterygii) from the Middle Triassic of Monte San Giorgio (Canton Tessin, Switzerland). Schweiz Paläont Abh, 114: 1–164.

Cavin L, Furrer H and Obrist C 2013. New coelacanth material from the Middle Triassic of eastern Switzerland, and comments on the taxic diversity of actinistans. Swiss J Geosci 106:161–177.

Cavin L et al (4 co-authors) 2017. Heterochronic evolution explains novel body shape in a Triassic coelacanth from Switzerland. Nature.com Scientific Reports 7: 13695 DOI:10.1038/s41598-017-13796-0

Fang G and Wu F 2022. The predatory fish Saurichthys reflects a complex underwater ecosystem of the Late Triassic Junggar Basin, Xinjiang, China. Historical Biology https://doi.org/10.1080/08912963.2022.2098023

Friedman M and Coates MI 2006. A newly recognized fossil coelcanth highlights the early morphological diversification of the clade. Proceedings B Biological Science 273(1583):245–250. online

Geng B-H, Zhu M and Jin F 2009. A revision and phylogenetic analysis of Guizhoucoelacanthus (Sarcopterygii, Actinistia) from the Triassic of China. Vertebratea PalAsiatica 7:165–177.

Giles S, Friedma M and Brazeau MD 2015. Osteichthyan-like cranial conditions in an Early Devonian stem gnathostome. Nature, 520 (7545): 82–85.

Jessen H 1973. Weitere fischreste aus dem Oberen Plattenkalk der Bergisch-Gladbach—Paffrather mulde (Oberdevon, Rheinesches Schiefergebirge) Palaeontogr. Abt. A. Palaeozool.-stratigr. 143:159–187.

Lehman J-P 1952. Etude complementaire des Poissons de l'Eotrias de Madagascar. K. Svenska Vetenskapsakad. Handl., ser. 4, bd. 2, no. 6:1–201

Liu G B, Yin G Z, Luo Y M et al 2006. Preliminary examination of fish fossils from Upper Triassic Wayao Member of Falang Formation in Guanling of Guizhou. Acta Palaeont Sin 45(1): 1-20.

Long JA 1999. A new genus of fossil coelacanth (Osteichthyes: Coelacanthiformes) from the Middle Devonian of southeastern Australia. Records of the Western Australian Museum Supplement 57:37–53.

Lund R and Lund W 1984. New genera and species of coelacanths from the Bear Gulch Limestone (Lower Carboniferous) of Montana (U.S.A.). Geobios. 17 (2): 237–244.

Melton WG 1969. A new dorypterid fish from central Montana. Northwest Science 43:196-206.

Münster GG 1834. Mitteilungen an Professor Bronn gerichtet.– Neues Jahrbuch fr Mineralogie, Geognosie, Geologie und Petrefakten-Kunde 1834: 538–542.

Olsen PE and McCune AR 1991. Morphology of the Semionotus elegans species group from the Early Jurassic part of the Newark Supergroup of eastern North America with comments on the Family Semionotidae (Neopterygii). Journal of Vertebrate Paleontology: 11(3):272.

Rieppel O 1980. A new coelacanth from the Middle Triassic of Monte San Giorgio, Switzerland. Eclogae geol. Helvetica 73/3:921–939.

Wendruff AJ and Wilson MVH 2012. A fork-tailed coelacanth, Rebellatrix divericerca, gen.et sp. nov. (Actinista, Rebellatricidae, fam. nov.), from the Lower Triassic of Western Canada. Journal of Vertebrate Paleontology 32(3):499–511.

Xu G-H 2020. A new species of Luganoia (Luganoiidae, Neopterygii) from the Middle Triassic Xingyi Biota, Guizhou, China. Vertebrata PalAsiatica 58(4):267–282.

wiki/Semionotus
wiki/Luganoia
wiki/Latimeria
wiki/Allenypterus
wiki/Actinistia
wiki/Coelacanth
wiki/Hadronector
wiki/Holopterygius
wiki/Coelacanthus
wiki/Guizhoucoelacanthus - not yet posted
wiki/Undina
wiki/Foreyia
wiki/Rebellatrix
wiki/Ticinepomis
wiki/Gavinia
wiki/Parasemionotus