Taxonomy and morphological diversity of infructescences Jenkinsella co-occurred with Trochodendroides leaves in the Cretaceous and Paleogene

Abstract

On the basis of new records and reexamination of described fossils a revision of morphology and systematics of fructifications, found in co-occurrence with Trochodendroides Berry leaves was undertaken. The general construction of racemose infructescences and fruits of all known specimens is practically identical. This similarity indicates that these plants were closely related with minor differences that are not sufficient for separate generic designation. We suggest applying the name Jenkinsella Reid et Chandler for dispersed follicular fruits, to fruits in racemes and to infructescences attached to the shoots. This is the earliest appropriate generic name designated for fruits with distinguishable morphology and critical details of inner structures. The diagnosis of the genus Jenkinsella is emended and five new species are described: Jenkinsella krassilovii Golovneva et P. Alekseev, sp. nov., J. knowltonii Golovneva et P. Alekseev, sp. nov., J. conferta P. Alekseev et Golovneva, sp. nov., J. makulbekovii Golovneva et P. Alekseev, sp. nov., J. vilyuensis Golovneva et P. Alekseev, sp. nov. Three new combinations (J. filatovii (Samylina) Golovneva et P. Alekseev, comb. nov., J. jiayinensis (G.P. Feng, C.S. Li, Zhilin, Y.F. Wang et Gabrielyan) Golovneva et P. Alekseev, comb. nov., J. gardnerii (Chandler) Golovneva et P. Alekseev, comb. nov.) are created. Investigation of infructescence arrangement in different species of Jenkinsella provides new data, allowing reinterpretation of fertile shoots construction in Joffrea speirsii.