Reconstruction of Weigeltaspis alta, copyright Apokryltaros.

Belongs within: Craniata.
Contains: Amphiaspidiformes, Cyathaspidiformes, Pteraspidiformes, Psammosteiformes.

The Pteraspidomorphi are an Ordovician to Devonian clade of jawless fishes bearing paired nasal sacs with separate openings and no nasohypophyseal canal (Bond 1996).

<==Pteraspidomorphi [Pteraspides]
| i. s.: Palaeospondylus gunniB96
|--+--Arandaspida [Arandaspidiformes, Arandaspidomorphi]MS16
| | | i. s.: *Anatolepis heintzi Bockelie & Fortey 1976TBN04, B96, H93
| | `--ArandaspididaeH93
| | |--Arandaspis prionotolepis Ritchie & Gilbert-Tomlinson 1977H93
| | `--Saccambaspis janvieri Gagnier 1987H93
| `--Astraspidiformes [Astraspida, Eriptychiformes]SS05
| |--Eriptychius Walcott 1892 [Eriptychiidae]SS05
| | `--*E. americanus Walcott 1892 [incl. E. orvigi Denison 1967, E. oervigi (l. c.)]SS05
| |--Porophoraspis [Porophoraspidae]H93
| | `--P. crenulata Ritchie & Gilbert-Tomlinson 1977H93
| |--Aseraspis [Aseraspididae]H93
| | `--A. canadensis Dineley & Loeffler 1976H93
| |--Lepidaspis [Lepidaspididae]H93
| | `--L. serrata Dineley & Loeffler 1976H93
| |--AstraspididaeH93
| | |--Tesakoviaspis concentrica Karatajute-Talimaa 1978H93
| | `--Astraspis Walcott 1892MS16, SS05 [incl. Pycnaspis Ørvig 1958SS05; Astraspididae]
| | `--*A. desiderata Walcott 1892 [incl. *Pycnaspis splendens Ørvig 1958, A. splendens]SS05
| `--Tesseraspididae [Tesseraspidida]H73
| |--TesseraspisH93
| | |--T. denisoni Halstead Tarlo 1965H93
| | `--T. tesselata Wills 1935BMM02
| |--Kallostrakon Lankester 1870H73, SM01
| | |--K. macanuffiH73
| | `--K. poduraH73
| `--Oniscolepis Pander 1856H73, P56
| |--O. crenulatus Pander 1856P56
| |--O. dentatus Pander 1856P56
| |--O. magnus Pander 1856P56
| `--O. serratus Pander 1856P56
| i. s.: Miltaspis anatirostrataMG01
| Athenaegis chattertoni Soehn & Wilson 1990SM01
| Belgicaspis crouchiE84
| Cardipeltis [Cardipeltidae, Cardipeltiformes]H93
| |--C. bryanti Denison 1966H93
| |--C. richardsoni Denison 1966H93
| `--C. wallacii Branson & Mehl 1931H93
| `--+--PteraspidiformesE84
| `--PsammosteiformesE84
|--Phialaspis [Phialaspididae]H93
| `--P. symondsi (Lankester 1866)H93
|--Traquairaspididae [Traquairaspidiformes]E84
| |--YukonaspisH73
| `--TraquairaspisH93
| |--T. campbelli (Traquair 1913) [incl. Phialaspis pococki var. cowiensis White 1946]H93
| `--T. pococki (White 1946)H93
|--Weigeltaspis [Weigeltaspididae]H93
| |--W. alta Brotzen 1933H93
| |--W. brotzeni Halstead Tarlo 1965H93
| |--W. godmani Halstead Tarlo 1965H93
| `--W. heintzi Halstead Tarlo 1965H93
| |--N. adunata Dineley & Loeffler 1976H93
| `--N. planicosta Dineley & Loeffler 1976H93
|--L. lemniscata (Dineley & Loeffler 1976)H93
|--L. mackenziensis (Dineley & Loeffler 1976H93
`--L. poolei (Dineley & Loeffler 1976)H93

*Type species of generic name indicated


[BMM02] Blom, H., T. Märss & C. G. Miller. 2002. Silurian and earliest Devonian birkeniid anaspids from the Northern Hemisphere. Transactions of the Royal Society of Edinburgh: Earth Sciences 92: 263–323.

[B96] Bond, C. E. 1996. Biology of Fishes 2nd ed. Saunders College Publishing: Fort Worth.

[E84] Elliott, D. K. 1984. A new subfamily of the Pteraspididae (Agnatha, Heterostraci) from the Upper Silurian and Lower Devonian of Arctic Canada. Palaeontology 27: 169–197.

[H73] Halstead, L. B. 1973. The heterostracan fishes. Biological Reviews 48: 279–332.

[H93] Halstead, L. B. 1993. Agnatha. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 573–581. Chapman & Hall: London.

[MG01] Märss, T., & P.-Y. Gagnier. 2001. A new chondrichthyan from the Wenlock, Lower Silurian, of Baillie-Hamilton Island, the Canadian Arctic. Journal of Vertebrate Paleontology 21 (4): 693–701.

[MS16] McCoy, V. E., E. E. Saupe, J. C. Lamsdell, L. G. Tarhan, S. McMahon, S. Lidgard, P. Mayer, C. D. Whalen, C. Soriano, L. Finney, S. Vogt, E. G. Clark, R. P. Anderson, H. Petermann, E. R. Locatelli & D. E. G. Briggs. 2016. The ‘Tully monster’ is a vertebrate. Nature 532: 496–499.

[P56] Pander, C. H. 1856. Monographie der Fossilen Fische des Silurischen Systems der Russisch-Baltischen Gouvernements. Buchdruckerei der Kaiserlichen Akademie der Wissenschaften: St Petersburg.

[SS05] Sansom, I. J., & M. P. Smith. 2005. Late Ordovician vertebrates from the Bighorn Mountains of Wyoming, USA. Palaeontology 48 (1): 31–48.

[SM01] Soehn, K. L., T. Märss, M. W. Caldwell & M. V. H. Wilson. 2001. New and biostratigraphically useful thelodonts from the Silurian of the Mackenzie Mountains, Northwest Territories, Canada. Journal of Vertebrate Paleontology 21: 651–659.

[TBN04] Turner, S., A. Blieck & G. S. Nowlan. 2004. Vertebrates (agnathans and gnathostomes). In: Webby, B. D., F. Paris, M. L. Droser & I. G. Percival (eds) The Great Ordovician Biodiversification Event pp. 327–335. Columbia University Press.

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