Westergaardodina was a long-lived paraconodont genus found from the Middle or Late Cambrian to the Middle Ordovician. It had W- or U-shaped elements that Müller & Hinz-Schallreuter (1998) explained as growing through a combination of dorsal and/or lateral pressure being applied to points on a growing element. How the Westergaardodina elements were arranged in their original apparatus remains unknown.
Characters (from Müller & Hinz-Schallreuter 1998): Bi- or tricuspidate elements; internal cavity may be divided between lateral cavities. Lateral projection(s) (one-sided only in bicuspidate forms) resulting from combination of upward growth from base and dorsal pressure alongside/on either side of median projection causing tearing of older lamellae; lamellae-free spaces became filled by a callus-like substance. Lateral projections of elements remain flexible; probably not heavily mineralised in life.
<==Westergaardodina Müller 1959 DJ71 | i. s.: W. mosseburgensis Müller 1959 DJ71 |--*W. bicuspidata Müller 1959 DJ71 `--+--W. amplicava Müller 1959 DJ71 `--Chosonodina Müller 1964 DJ71 | i. s.: C. rigbyi PBJ03 |--C. fisheri Druce & Jones 1971 DJ71 `--+--*C. herfurthi Müller 1964 DJ71 `--+--C. lunata Harris & Harris 1965 DJ71 `--Coleodus Branson & Mehl 1933 DJ71, SS05 `--C. simplex DJ71
* Type species of generic name indicated
[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.
Müller, K. J., & I. Hinz-Schallreuter. 1998. Internal structure of Cambrian conodonts. Journal of Paleontology 72 (1): 91-112.
[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.
[SS05] Sansom, I. J., & M. P. Smith. 2005. Late Ordovician vertebrates from the Bighorn Mountains of Wyoming, USA. Palaeontology 48 (1): 31-48.
Christopher 13:17, 6 January 2011 (UTC)