Fungalpedia – Note 230, Palaeoamphisphaerella (Fossil Fungi)

 

Palaeoamphisphaerella Ramanujam & Srisailam.

Citation when using this entry: Saxena RK & Hyde KD. 2024 (in prep) – Fungalpedia, Fossil Fungi. 

Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1            

Classification: Hypoxylaceae, Xylariales, Sordariomycetes, Fossil Ascomycota. 

Ramanujam & Srisailam (1980) instituted the fossil genus, Palaeoamphisphaerella, from the Miocene (23–5 mya) sediments of Palayangadi, Kannur District, and Cheruvattur (southern side of Karingottu River), Kasaragod District, Kerala, India. This genus is characterized by brownish to dark brown, aseptate, elliptical, oblong, or somewhat rhomboidal spores with rounded ends. The pores were equatorial and equidistant. The surface was scanned at a psilate-to-scan rate. 

According to Ramanujam & Srisailam (1980), equatorially disposed pores are a characteristic feature of this genus. The fossil spores exhibited a remarkable resemblance to the ascospores of the extant Amphisphaerella Henn. (Current name: Rosellinia De Not). According to Eriksson (1966), the distinctive feature of Amphisphaerella is the equatorial and more or less equidistant pores in ellipsoidal, aseptate, and dark brown ascospores. According to Kalgutkar & Jansonius (2000), Palaeoamphisphaerella appears indistinguishable from Imprimospora in general and diagnostic morphology, and therefore Imprimospora is considered a later synonym of Palaeoamphisphaerella.

Taxonomic synonym: Imprimospora G. Norris 1986 fide Kalgutkar & Jansonius (2000).

Type species: Palaeoamphisphaerella pirozynskii Ramanujam and Srisailam.

 

 

Figure 1 – Palaeoamphisphaerella pirozynskii. Scale bar = 10 μm. Redrawn from Ramanujam & Srisailam (1980).

 

References

Eriksson O. 1966 – On Anthostomella Sacc., Entosordaria (Sacc.) v. Hohn. and some related genera (Pyrenomycetes). Svensk Botanisk Tidskrift 60, 315–324. 

Kalgutkar RM, Jansonius J. 2000 – Synopsis of fungal spores, mycelia and fructifications. AASP Contribution Series 39, 1–423.

Norris G. 1986 – Systematic and stratigraphic palynology of Eocene to Pliocene strata in the Imperial Nuktak C–22 well, Mackenzie Delta Region, District of Mackenzie, N.W.T. Geological Survey of Canada Bulletin, 340, 89 p. 

Ramanujam CGK, Srisailam K. 1980 – Fossil fungal spores from the Neogene Beds around Cannanore in Kerala state. Botanique 9, 119–138.

 

Entry by

Ramesh K. Saxena, Birbal Sahni Institute of Palaeosciences, Lucknow, India

 

(Edited by Kevin D. Hyde, Samaneh Chaharmiri-Dokhaharani, & Achala R. Rathnayaka)

Published online 3 April 2024

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