megalosphericadj.
/ˌmɛɡələ(ʊ)ˈsfɛrɪk/, /ˌmɛɡl̩ə(ʊ)ˈsfɛrɪk/, U.S. /ˌmɛɡ(ə)loʊˈsfɛrɪk/, /ˌmɛɡ(ə)ləˈsfɛrɪk/ Zoology.
Designating or relating to one of the two forms of a dimorphic foraminiferan, in which the proloculus or first-formed chamber of the shell is relatively large. Cf. microspheric adj.
ΘΚΠ
the world > animals > invertebrates > protozoa > class Sarcodina > order Rhizopoda > [adjective] > relating to Foraminifera
orbitoid1852
foraminiferal1865
megalospheric1896
1896 J. J. Lister in Philos. Trans. 1895 (Royal Soc.) B. 186 401 Munier-Chalmas and Schlumberger distinguish the two groups as Form A, with a megasphere, and Form B, with a microsphere. I have ventured to modify one of these terms, and refer to the forms as megalospheric (with a large central chamber), and microspheric (with a small central chamber) respectively.
1946 H. Woods Palaeontol. Invertebr. (ed. 8) 21 The relationship of the microspheric and megalospheric shells has been elucidated by a study of the life-history of Polystomella and other living Foraminifera.
1952 R. C. Moore et al. Invertebr. Fossils ii. 40/2 The size of the proloculus of megalospheric forms varies considerably in certain species.
1963 G. A. Kerkut Borradaile & Potts's Invertebrata (rev. ed.) ii. 80 In many species [of Polythalamia] the shells are dimorphic, the two forms..being distinguished by the size and arrangement of the first-formed chamber, which is small in one (the microspheric form) and larger in the other (megalospheric).
1993 Jrnl. Eukaryotic Microbiol. 40 719/1 Seven of the nine parental specimens..were identified as megalospheric, hence schizonts.
This entry has been updated (OED Third Edition, June 2001; most recently modified version published online March 2022).
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adj.1896