Cupressaceae BARTLETT

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

Family Cupressaceae BARTLETT

Genus cf. Metasequoia MIKI

Text-fig. 2d, e

M a t e r i a l. USNM PAL 622101, 717666.

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

D e s c r i p t i o n. Winged seed round to rectangular with wings forming retuse connection at poles; 0.7–1.0 mm tall, 0.6 mm wide; seed body elliptical, in the center of the wings; polar ends of seed body in line with polar ends of wings; seed body 0.3–0.7 mm long, 0.2 mm wide.

R e m a r k s. This seed bears a superficial resemblance to those of Metasequoia which has also been identified based on foliage from the Kishenehn Formation ( Text-fig. 2f ; USNM PAL 776571, 2g USNM PAL 776572). However, the extant Metasequoia glyptostroboides HU et W.C. CHENG has seeds that range between 4.2–5 mm long and 4.8– 6 mm wide, about 4–5 times larger than the Kishenehn specimen (eFloras 2008–2022, Liu and Basinger 2009). Fossil Metasequoia seeds from other sites are also larger (e.g., 5–6 mm long and 6–7 mm wide; Falder et al. 1999). Metasequoia is a major component of the Early Eocene Falkland flora of British Columbia ( Smith et al. 2012).

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.