Micrina

Micrina is an extinct genus of tommotiids with affinities to brachiopods.^[1]

Micrina
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Stem group:	†"Tommotiida"
Genus:	†Micrina Laurie, 1986
Type species
Platyceras etheridgei Tate, 1892
Species
M. etheridgei M. pusilla M. ridicula M. xiaotanensis

Micrina can be considered a stem group brachiopod based on its larval shell^[2]

Its microstructure is very brachiopod like^[3] and its adult morphology is similarly bivalved,^[4] even though it was once thought to be halkieriid-like.^[5]

Micrina is quite similar to Mickwitzia in terms of shell microstructure. The two genera are evidently closely related.

Species

• M. etheridgei (Tate, 1892)
• M. pusilla Gravestock et al., 2001
• M. ridicula (Barskova, 1988)
• M. xiaotanensis Li & Xiao, 2004^[6]

References

1. McMenamin, M. A. S. (1992). "Two new species of the Cambrian genus Mickwitzia". Journal of Paleontology. 66 (2): 173–182. doi:10.1017/S0022336000033680. JSTOR 1305903. S2CID 132405917.
2. Holmer L. E., Skovsted C. B., Larsson C., Brock G. A., Zhang Z. (2011). "First record of a bivalved larval shell in Early Cambrian tommotiids and its phylogenetic significance". Palaeontology. 54 (2): 235–239. doi:10.1111/j.1475-4983.2010.01030.x.{{cite journal}}: CS1 maint: multiple names: authors list (link)
3. Balthasar U., Skovsted C. B., Holmer L. E., Brock G. A. (2009). "Homologous skeletal secretion in tommotiids and brachiopods". Geology. 37 (12): 1143–1146. Bibcode:2009Geo....37.1143B. doi:10.1130/g30323a.1.{{cite journal}}: CS1 maint: multiple names: authors list (link)
4. Holmer L. E., Skovsted C. B., Brock , Valentine J. L., Paterson J. R. (2008). "The Early Cambrian tommotiid Micrina, a sessile bivalved stem group brachiopod". Biol. Lett. 4 (6): 724–728. doi:10.1098/rsbl.2008.0277. PMC 2614141. PMID 18577500.{{cite journal}}: CS1 maint: multiple names: authors list (link)
5. Holmer L. E., Skovsted C. B., Williams A. (2002). "A stem group brachiopod from the lower Cambrian: support for a Micrina (Halkieriid) ancestry". Palaeontology. 45 (5): 875–882. doi:10.1111/1475-4983.00265.{{cite journal}}: CS1 maint: multiple names: authors list (link)
6. Li G.-X., Xiao S.-H. (2004). "Tannuolina and Micrina (Tannuolinidae) from the Lower Cambrian of Eastern Yunnan, South China, and Their Scleritome Reconstruction". J. Paleontol. 78 (5): 900–913. doi:10.1666/0022-3360(2004)078<0900:TAMTFT>2.0.CO;2. JSTOR 4094916. S2CID 131286565.