Protopanderodontida

Protopanderodontida; Temporal range: Descendant taxa Panderodontida and Prioniodontida survive to the Middle Devonian and Late Triassic, respectively
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Infraphylum:	Agnatha
Class:	†Conodonta
Clade:	†Euconodonta
Order:	†Protopanderodontida; Sweet, 1988
Synonyms
	Distacodontacea Miller, 1981;

Protopanderodontida is an order of conodonts which lived from the Furongian (Late Cambrian) to the Wenlock (mid-Silurian). They had a relative simple apparatus with several pairs of coniform elements (single-cusped tooth-like structures) in the mouth, lacking the more elaborate arrangements found in "complex conodonts" (Prioniodontida).^[1]

Protopanderodontids were a common component of Ordovician conodont faunas, and were probably a grade ancestral to later conodonts in the orders Panderodontida and Prioniodontida. They may have been the earliest conodonts with an odd number of elements in the jaw. A single median symmetrical element (the S₀ element) is found at the midline of the apparatus, potentially originating from a fusion of paired coniform elements in an earlier ancestor.^[2] The only putative protopanderodontid to preserve an articulated partial apparatus is Besselodus arcticus, from the Late Ordovician of Greenland.^[3]^[4]^[5]

^ Sweet, W. C. (1988). The Conodonta: morphology, taxonomy, paleoecology and evolutionary history of a long-extinct animal phylum. Oxford Monographs on Geology and Geophysics. Vol. 10. pp. 1–211. ISBN 978-0-19-504352-5.
^ Dzik, Jerzy (2015). "Evolutionary roots of the conodonts with increased number of elements in the apparatus" (PDF). Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 106 (1): 29–53. doi:10.1017/S1755691015000195. ISSN 1755-6910.
^ Aldridge, R.J. (1982). "A fused cluster of coniform conodont elements from the late Ordovician of Washington Land, western north Greenland" (PDF). Palaeontology. 25 (2): 425–430.
^ Samson, Ivan J.; Armstrong, Howard A.; Smith, M. Paul (1994). "The apparatus architecture of Panderodus and its implications for coniform conodont classification" (PDF). Palaeontology. 37 (4): 781–799.
^ Murdock, Duncan J. E.; Smith, M. Paul (2021). Sansom, Robert (ed.). "Panderodus from the Waukesha Lagerstätte of Wisconsin, USA: a primitive macrophagous vertebrate predator". Papers in Palaeontology. 7 (4): 1977–1993. doi:10.1002/spp2.1389. ISSN 2056-2799.

[:3-1] Sweet, W. C. (1988). The Conodonta: morphology, taxonomy, paleoecology and evolutionary history of a long-extinct animal phylum. Oxford Monographs on Geology and Geophysics. Vol. 10. pp. 1–211. ISBN 978-0-19-504352-5.

[:1-2] Dzik, Jerzy (2015). "Evolutionary roots of the conodonts with increased number of elements in the apparatus" (PDF). Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 106 (1): 29–53. doi:10.1017/S1755691015000195. ISSN 1755-6910.

[:2-3] Aldridge, R.J. (1982). "A fused cluster of coniform conodont elements from the late Ordovician of Washington Land, western north Greenland" (PDF). Palaeontology. 25 (2): 425–430.

[4] Samson, Ivan J.; Armstrong, Howard A.; Smith, M. Paul (1994). "The apparatus architecture of Panderodus and its implications for coniform conodont classification" (PDF). Palaeontology. 37 (4): 781–799.

[5] Murdock, Duncan J. E.; Smith, M. Paul (2021). Sansom, Robert (ed.). "Panderodus from the Waukesha Lagerstätte of Wisconsin, USA: a primitive macrophagous vertebrate predator". Papers in Palaeontology. 7 (4): 1977–1993. doi:10.1002/spp2.1389. ISSN 2056-2799.

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