Drepanoistodontidae

Element of Drepanoistodus suberectus, copyright Olle Hints.

Belongs within: Conodonti.

The Drepanoistodontidae are a group of conodonts known from the Ordovician possessing apparatus composed of recurved and/or geniculate coniform elements (Sweet 1988). Members of this family comprise the core of what has been recognised as the form-family Distacodontidae; however, the use of this latter name was discouraged by Sweet (1988) due to the type genus Distacodus being a nomen dubium of uncertain affinities.

<==Drepanoistodontidae [Distacodontacea, Distacodontidae] S88
    |--Acodina Stauffer 1940 H62
    |    `--A. cuspidata (Stauffer 1940) WSQ86
    |--Proacodus Müller 1959 M62
    |    `--*P. obliquus Müller 1959 M62
    |--Acontiodus Pander 1856 H62
    |    |--*A. latus Pander 1856 H62
    |    `--A. franconicus LM05
    |--Distacodus Pander 1856 (n. d.) S88 [=Machairodus Pander 1856 non Kaup 1833 H62; incl. Machairodia Smith 1907 H62]
    |    |--*D. incurvus (Pander 1856) [=*Machairodus incurvus] H62
    |    `--D. ensiformis H62
    |--Furnishina Müller 1959 M62
    |    |--*F. furnishi Müller 1959 M62, DJ71 [=Sagittodontus furnishi DJ71]
    |    |--F. alata Szaniawski 1971 RNP03
    |    `--F. polonica Szaniawski 1971 RNP03
    |--Paltodus Pander 1856 S88, H62
    |    |--*P. subequalis Pander 1856 H62
    |    |--P. deltifer J79
    |    |--P. jemtlandicus PBJ03
    |    |--P. spurius LM05
    |    `--P. truncatus H62
    |--Paroistodus Lindström 1971 S88
    |    |--P. horridus (Barnes & Poplawski 1973) S88
    |    |--P. numarcuatus S88
    |    |--P. originalis PBJ03
    |    |--P. parallelus PBJ03
    |    `--P. proteus PBJ03
    `--Drepanoistodus Lindström 1971 SS05
         |--*D. forceps (Lindström 1955) [=Oistodus forceps] SS05
         |--D. angulensis PBJ03
         |--D. basiovalis PBJ03
         |--D. concavus PBJ03
         |--D. latus PBJ03
         |--D. lucidus PBJ03
         `--D. suberectus (Branson & Mehl 1933) SS05 (see below for synonymy)

Drepanoistodus suberectus (Branson & Mehl 1933) SS05 [=Oistodus suberectus SS05, Drepanodus suberectus DJ71; incl. D. homocurvatus DJ71, Oistodus inclinatus DJ71]

*Type species of generic name indicated

REFERENCES

[DJ71] Druce, E. C., & P. J. Jones. 1971. Cambro-Ordovician conodonts from the Burke River Structural Belt, Queensland. Commonwealth of Australia, Bureau of National Development, Bureau of Mineral Resources, Geology and Geophysics, Bulletin 110: 1–159.

[H62] Hass, W. H. 1962. Conodonts. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt W. Miscellanea: Conodonts, Conoidal Shells of Uncertain Affinities, Worms, Trace Fossils and Problematica pp. W3–W69. Geological Society of America, and University of Kansas Press.

[J79] Jaanusson, V. 1979. Ordovician. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A136–A166. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[LM05] Lehnert, O., J. F. Miller, S. A. Leslie, J. E. Repetski & R. L. Ethington. 2005. Cambro-Ordovician sea-level fluctuations and sequence boundaries: the missing record and the evolution of new taxa. Special Papers in Palaeontology 73: 117–134.

[M62] Müller, K. J. 1962. Supplement to systematics of conodonts. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt W. Miscellanea: Conodonts, Conoidal Shells of Uncertain Affinities, Worms, Trace Fossils and Problematica pp. W246–W249. Geological Society of America, and University of Kansas Press.

[PBJ03] Pyle, L. J., C. R. Barnes & Z. Ji. 2003. Conodont fauna and biostratigraphy of the Outram, Skoki, and Owen Creek Formations (Lower to Middle Ordovician), Wilcox Pass, Alberta, Canada. Journal of Paleontology 77 (5): 958–976.

[RNP03] Robson, S. P., G. S. Nowlan & B. R. Pratt. 2003. Middle to Upper Cambrian linguliformean brachiopods from the Deadwood Formation of subsurface Alberta and Saskatchewan, Canada. Journal of Paleontology 77 (2): 201–211.

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

[S88] Sweet, W. C. 1988. The Conodonta: Morphology, taxonomy, paleoecology, and evolutionary history of a long extinct animal phylum. Clarendon Press: Oxford.

[WSQ86] Wang C.-Y., Shi C.-G. & Qu G.-S. 1986. Conodonts and ostracodes from the Devonian “Heitai Formation” of Mishan County, Heilongjiang Province. Acta Micropalaeontologica Sinica 3 (2): 205–214.