Pinales GOROZHANKIN

Smith, MacKenzie A., Greenwalt, Dale E. & Manchester, Steven R., 2023, Diverse Fruits And Seeds Of The Mid-Eocene Kishenehn Formation, Northwestern Montana, Usa, And Their Implications For Biogeography, Fossil Imprint 79 (1), pp. 37-88 : 40

Order Pinales GOROZHANKIN

Coniferae 1

Text-fig. 2b

M a t e r i a l. USNM PAL 622297.

L o c a l i t y. Disbrow Creek.

D e s c r i p t i o n. Conifer leaf 19.3 mm long, 3.8 mm wide; petiole stout and rectangular, 0.8 mm long and 0.9 mm wide; leaf base asymmetrical, obtuse and rounded; apex not preserved or in matrix; midvein 0.6 mm; a pair of stomatal bands runs on both sides of the midvein, running parallel to it. Width of the stomatal bands varying between 0.2–0.3 mm.

R e m a r k s. The affinities of this leaf remain is uncertain. Prominent stomatal bands can be found in leaves of Taxaceae ( Amentotaxus PILG. , Cephalotaxus SIEBOLD et ZUCC. ex ENDL. , Taxus L.), Cupressaceae ( Sequoia ENDL. ) and Pinaceae ( Abies L., Pseudotsuga CARRIÈRE and Tsuga (ENDL.) CARRIÈRE ). However, these taxa have stomatal bands as wide or wider than the midvein, whereas our specimen has stomatal bands half of the width of the midvein. The leaf has narrower stomatal bands than those that have been recorded for Amentotaxus PILG. (eFloras 2008–2022). Modern Amentotaxus has leaves that are 20–115 mm long, 5–15 mm wide and with stomatal bands 1–2 mm wide (eFloras 2008–2022).

Figures

Text-fig. 2. Equisetum and conifers from the Kishenehn Formation. a: USNM PAL 620616 Equisetum sp. stem apex. Scale bar 3mm. b: USNM PAL 622297 Coniferae 1. Scale bar 5mm. c: USNM PAL 622081 Coniferae 2. Scale bar 2mm. d: USNM PAL 717666 cf. Metasequoia sp. seed. Scale bar 1mm. e: USNM PAL 622101 cf. Metasequoia sp. seed. Scale bar 1mm. f: USNM PAL 776571 Metasequoia sp. twig showing opposite leaves. Scale bar 10mm g: USNM PAL 776572 Metasequoia sp. twigs. Scale bar 10 mm. h: USNM PAL 621667 Juniperus sp. leafy twig. Scale bar 5mm. i: USNM PAL 722223 Juniperus sp. twig. Scale bar 2mm. Scale bar 3mm. j: USNM PAL 623467 unidentified Cupressoideae 1. Scale bar 3mm. k: USNM PAL 620274 unidentified Cupressoidae 2 leaves. l: USNM PAL 620087 unidentified Cupressoideae 2. Scale bar 1mm. m: USNM PAL 620184 unidentified Cupresseoideae 3 shoot. Scale bar 2mm. n: USNM PAL 621863 Cupressoideae 4 leafy twig. Scale bar 5mm.