Home Page

Next Page

SARCOPTERYGII Actinistia and Dipnomorpha

This group is characterised by the articulation of the paired fins, with the fin musculature extending into the basal lobe and the entire tooth being covered with enamel. Their fossil record starts in the early Devonian although the more primitive taxa seem to appear later indicating the stratigraphical distribution does not match closely the current accepted pattern of their interrelationships and hence much of their development must have occurred much earlier than the fossil record would suggest.

The Sarcopterygians are divided into 7 groups

Onychodontiformes, Actinistia (including the extant coelacanth, Latimeria), Dipnomorpha (including the Dipnoi, lungfishes), Rhizodontiformes, Osteolepiformes, Panderichthydia and the Tetrapoda.


The fossil record begins in the Giventian, with the number of species increasing from the Devonian to Carboniferous, they decrease in the Permian, peak in the Triassic, decrease to the end of the Cretaceous, then disappear from the fossil record from the Tertiary. The early Coelacanths such as Miguashaia show remarkable similarities to the extant form, Latimera.

Actinista in my collection (click on thumbnails to see larger images)

Caridosuctor populosum        Mississippian        Bear Gulch, USA

aa-fish-coel-pos.jpg (49134 bytes)  Pos          aa-fish-coel-neg.jpg (41491 bytes)   neg            aa-fish-coel-pos-tail.jpg (34850 bytes)  tail


 Chinlea Sorenseni  Triassic   Colorado  USA 

Exact spec. described Elliott, D.K 1987. A new specimen of Chinlea Sorenseni from the Chinle Formation, Delores River, Colorado. Journal of the Arizona-Nevada Academy of Science 22:47-52

ss-co4.jpg (30467 bytes)    ss-co1.jpg (24892 bytes)    ss-co2.jpg (27547 bytes)  

chin3.jpg (117095 bytes)  chin2.jpg (111686 bytes)  chin.jpg (178778 bytes)  All taken from Elliot 1987


n-co1.jpg (44742 bytes)   n-co2.jpg (42325 bytes)    Whiteia woodwardi      Permian,    Madagascar 


rhabdo1.jpg (115965 bytes)   rhabdo2.jpg (122584 bytes)   k-mazoncoel.jpg (64819 bytes)       Rhabdoderma sp.       Upper Carboniferous    Mazon creek,   USA




The Porolepiformes and Dipnoi are the two major taxa.

The Porolepiformes or holoptychids as they are also known are exclusively Devonian fish with stout bodies, a blunt snout, an epiceral tail, long leaf-shaped pectoral fins and strongly folded teeth (shared with the osteolepiformes)

glypto.jpg (78224 bytes)  glyptohead.jpg (137570 bytes)   Glyptolepis paucidens      Mid Devonian      Achanarras, Scotland

The Dipnoi are best characterised by large toothplates that derive from modifications of the entopterygoids and prearticular. Other than having more heavily ossified sketetons and being much more diverse, the Devonian Lungfish are very similar to extant examples. Given their presumed relationship to the Tetrapods, this taxa is always subject to much debate.

Dipnoi in my collection (click on thumbnails to see larger images)

Dipterus vallenciennesi     

ss-monsterdip.jpg (47855 bytes)   ss-monsterdiphead.jpg (93024 bytes)     Mid Devonian      Achanarras, Scotland  very large (O.macrolepidotus for scale)

 y-doubdip.jpg (72892 bytes)   ss-diptfins.jpg (87289 bytes)     Mid Devonian      Achanarras, Scotland      note good pectoral fins

y-assoc.jpg (82648 bytes)       Mid Devonian      Caithness, Scotland      Osteolepis association plate


p-pentlandia.jpg (150944 bytes)     ss-penttail.jpg (86597 bytes)   Pentlandia macroptera   Mid Devonian      Caithness, Scotland 

gg-cob.jpg (43398 bytes)   Sagenodus obligatus (upper jaw and tooth), Newsham,UK


Scaumenacia curata  Upper Devonian Escuminac Formation,  Miguasha, Quebec, Canada

scaum.jpg (48536 bytes)  scaumtail.jpg (90228 bytes)                           

ss-scaumtra.jpg (88797 bytes)


k-dipmouthplate.jpg (84656 bytes)    Dipnotuberculus gnathodus       Mid Devonian      Mader, Morocco

ss-dipnoidentary.jpg (68873 bytes)  ss-dipnoidentary2.jpg (68849 bytes)    Similar to above.........


ss-mazon.jpg (37630 bytes)     Esconichthys apopyris       Upper Carboniferous    Mazon creek   USA




SARCOPTERYGII Images from 'Dura Den - A monograph of the Yellow sandstone' 1859 J Anderson

tt-duraglypto.jpg (82208 bytes)         tt-duraglypto2.jpg (60866 bytes)        tt-duraholop.jpg (60840 bytes)       tt-duraphan1.jpg (56295 bytes)