PREMISE OF THE STUDY: Fossilized seeds similar to Cissus (Vitaceae) have been recognized from the Miocene of Kenya, though some were previously assigned to the Menispermaceae. We undertook a comparative survey of extant African Cissus seeds to identify the fossils and consider their implications for the evolution and biogeography of Cissus and for African early Miocene paleoenvironments.
METHODS: Micro-computed tomography (µCT) and synchrotron-based X-ray tomographic microscopy (SRXTM) were used to study seed morphology and anatomy. Virtual taphonomy, using SRXTM data sets, produced digital fossils to elucidate seed taphonomy. Phylogenetic relationships within Cissus were reconstructed using existing and newly produced DNA sequences for African species. Paleobiology and paleoecology were inferred from African nearest living relatives.
KEY RESULTS: The fossils were assigned to four new Cissus species, related to four modern clades. The fossil plants were interpreted as climbers inhabiting a mosaic of riverine woodland and forest to more open habitats. Virtual taphonomy explained how complex mineral infill processes concealed key seed features, causing the previous taxonomic misidentification. Newly sampled African species, with seeds most similar to the fossils, belong to four clades within core Cissus, two of which are early diverging.
CONCLUSIONS: Virtual taphonomy, combined with X-ray imaging, has enabled recognition of the first fossil Cissus and Vitaceae from Africa. Early-divergent members of the core Cissus clade were present in Africa by at least the early Miocene, with an African origin suggested for the Cissus sciaphila clade. The fossils provide supporting evidence for mosaic paleoenvironments inhabited by early Miocene hominoids.
Cissus barbeyana SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus barbeyana De Wild. & T.Durand (K Herbarium sheet collector no. 16406)
Cibar521Liso16406 SRXTM DTS.mpg
Cissus bosseri SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus bosseri Desc. (K Herbarium sheet collector no. 3140)
Cibos530Phill3140 SRXTM DTS.mpg
Cissus dasyantha SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus dasyantha Gilg & M.Brandt (BR Herbarium sheet collector no. 13410)
Cidas516Loui13410 SRXTM DTS.mpg
Cissus dinklagei SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through the lowermost part of a herbarium fruit of Cissus dinklagei Gilg & M.Brandt (K Herbarium sheet collector no. 5207)
Cidin520Leeu5207 SRXTM DTS.mpg
Cissus integrifolia 1 SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus integrifolia (Baker) Planch. (K Herbarium sheet collector no. 8517, a)
Ciint534Tayl8517 SRXTM DTS.mpg
Cissus integrifolia 2 SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus integrifolia (Baker) Planch. (K Herbarium sheet collector no. 8517, b)
Ciint535Tayl8517 SRXTM DTS.mpg
Cissus lebrunii SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus lebrunii Dewit (K Herbarium sheet collector no. 1592)
Cileb523Nkon1592 SRXTM DTS.mpg
Cissus oreophila SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus oreophila Gilg & M.Brandt (K Herbarium sheet collector no. 693)
Ciore525Harl693 SRXTM DTS.mpg
Cissus petiolata SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus petiolata Hook.f. (K Herbarium sheet collector no. 492)
Cipet519Kefr492 SRXTM DTS.mpg
Cissus pileata SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus pileata Desc. (K Herbarium sheet collector no. 18981)
Cipil531Humb18981 SRXTM DTS.mpg
Cissus planchoniana SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus planchoniana Gilg (K Herbarium sheet collector no. 606)
Cipla526Roby606 SRXTM DTS.mpg
Cissus polyantha 1 SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus polyantha Gilg & M.Brandt (K Herbarium sheet collector no. 5208)
Cipol537Deig5208 SRXTM DTS.mpg
Cissus polyantha 2 SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus polyantha Gilg & M.Brandt (K Herbarium sheet collector no. 1643)
Cipol538Saca1643 SRXTM DTS.mpg
Cissus populnea SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus populnea Guill. & Perr. (K Herbarium sheet collector no. 350)
Cipop528Olde350 SRXTM DTS.mpg
Cissus rondoensis SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus rondoensis Verdc. (K Herbarium sheet collector no. 523)
Ciron529Bidg1553 SRXTM DTS.mpg
Cissus sciaphila SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus sciaphila Gilg (K Herbarium sheet collector no. 101)
Cisci545Adam101 SRXTM DTS.mpg
Cissus smithiana SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus smithiana (Baker) Planch. (K Herbarium sheet collector no. 416)
Cismi522Huls416 SRXTM DTS.mpg
Cissus tiliifolia SRXTM DTS video
Video of digital SRXTM tomograms in transverse section through a herbarium fruit of Cissus tiliifolia Planch. (K Herbarium sheet collector no. 240)
Citil524Eilu240 SRXTM DTS.mpg
Cissus dinklagei µCT DTS video
Video of digital µCT tomograms in transverse section through a herbarium fruit of Cissus dinklagei Gilg & M.Brandt (K Herbarium sheet collector no. 5207)
Cidin520Ieeu5207 µCT DTS.mpg
Cissus integrifolia 1 µCT DTS video
Video of digital µCT tomograms in transverse section through a herbarium fruit of Cissus integrifolia (Baker) Planch. (K Herbarium sheet collector no. 8517, a)
Ciint534Tayl8517 µCT DTS.mpg
Cissus integrifolia 2 µCT DTS video
Video of digital µCT tomograms in transverse section through a herbarium fruit of Cissus integrifolia (Baker) Planch. (K Herbarium sheet collector no. 8517, b)
Ciint535Tayl8517 µCT DTS.mpg
Cissus populnea µCT DTS video
Video of digital µCT tomograms in transverse section through a herbarium fruit of Cissus populnea Guill. & Perr. (K Herbarium sheet collector no. 350)
Cipop528Olde350 µCT DTS.mpg
Cissus crenulata µCT DTS video
Video of digital µCT tomograms in transverse section through a fossilized seed (the holotype) of Cissus crenulata Adams, Collinson, S.Y. Smith & Bamford comb. nov. (NHMUK specimen V33753)
V33753 µCT DTS.mpg
Cissus andrewsii µCT DTS video
Video of digital µCT tomograms in transverse section through a fossilized seed (the holotype) of Cissus andrewsii Adams, Collinson, S.Y. Smith & Bamford sp. nov. (NHMUK specimen V68501)
V68501 µCT DTS.mpg
Cissus rusingensis (holotype) µCT DTS video
Video of digital µCT tomograms in transverse section through a fossilized seed (the holotype) of Cissus rusingensis Adams, Collinson, S.Y. Smith & Bamford sp. nov. (KNM specimen R117.1981.314)
R117.1981.314 µCT DTS.mpg
Cissus rusingensis (paratype) µCT DTS video
Video of digital µCT tomograms in transverse section through a fossilized seed (a paratype) of Cissus rusingensis Adams, Collinson, S.Y. Smith & Bamford sp. nov. (KNM specimen R117.1981.476)
R117.1981.476 µCT DTS.mpg
Cissus psilata µCT DTS video
Video of digital µCT tomograms in transverse section through a fossilized seed (the holotype) of Cissus psilata Adams, Collinson, S.Y. Smith & Bamford sp. nov. (NHMUK specimen V68506)
V68506 µCT DTS.mpg