Supplementary material. A synthesis of Gnetalean macrofossil species from the Early Cretaceous

Species / Nomenclature / Distribution / Literature / Comments
Alloephedra xingxueii J.R. Tao et Y. Yang / Syn.: Ephedra xingxuei (J.R. Tao et Y. Yang) Liu et al. in Taxon, 57: 580. 2008 / Dalazi Formation. Aptian-Albian, Early Cretaceous. Jilin Province, China / Tao Yang 2003 / The female cone shows general features of Ephedraceae, but the foliar organs and branching patterns seem alternate thus Alloephedra differs from known Ephedra.
Amphiephedra rhamnoides Miki / Jehol (Yixian Formation?), western Liaoning of China / Miki 1964 / This is a shoot preserved with no details, probably close to Prognetella minuta Krassilov et Bugdaeva, exact relationships cannot be determined due to unclear reproductive morphology.
Beipiaoa parva Dilcher et al. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Sun et al. 2001 / A female cone is globose or nearly so, the apices of bracts are specialized into long spines.
Beipiaoa rotunda Dilcher et al. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Sun et al. 2001 / A female cone is globose or nearly so, the apices of bracts are specialized into long spines. This species is better incorporated into Beipiaoa parva due to their overall similarities.
Beipiaoa spinosa Dilcher et al. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Sun et al. 2001 / A female cone is globose or nearly so, the apices of bracts are specialized into long spines.
Chengia elegans (G. Sun et S.L. Zheng) Y. Yang et Q. Wang, comb. nov. / Basionym: Ephedrites elegans G. Sun et S.L. Zheng in Sun et al., Early Angiosperms and their associated plants from western Liaoning, China, 207. 2001. / Yixian Formation, western Liaoning of China; Gurvan-Eren Formation of Mongolia / An Ephedroid reproductive shoot possesses loosely arranged female spikes. The Potamogeton-like spike in Krassilov (1982) may belong to this species.
Chengia laxispicata Y. Yang et al. / Dawangzhangzi Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Yang et al. 2013 / An Ephedroid reproductive shoot bears terminal or axillary female spikes with multiple pairs of fertile bracts, internodes of the cone axis are prominent.
Drewria potomacensis Crane et Upchurch / Potomac Group. Pollen Zone I, Early Cretaceous (early Aptian). USA / Crane Upchurch 1987 / This species is intermediate between Ephedra and Welwitschia, its habit is close to Ephedra, but its leaf form and venation are close to Welwitschia.
Ephedra archaeorhytidosperma Y. Yang et al. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Yang et al. 2005 / An Ephedroid reproductive shoot has reduced female cones with only 1(-2?) pairs of bracts enclosing 1-2 seeds.
Ephedra carnosa Y. Yang et Q. Wang / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Yang Wang 2013 / A fleshy female cone of Ephedra contains 2-3 FRUs/seeds. Each FRU possesses a thin outer envelope, the inner integument is elongated into the micropylar tube.
Ephedra drewriensis Rydin et al. / Patuxent Formation, Potomac Group. Pollen Zone I, Early Cretaceous (early Aptian). USA / Rydin et al. 2006a / Ephedroid seeds have in situ pollen.
Ephedra hongtaoi X. Wang et S.L. Zheng / Dawangzhangzi Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Wang Zheng 2010 / An Ephedroid shrubby plant bears young female cones terminally on twigs. Each cone possesses a pair of bracts enclosing 2 FRUs/seeds. Each FRU has an apical micropylar tube.
Ephedra portugallica Rydin et al. / Calvaria Member, Figueira da Foz Formation. Early Cretaceous (late Aptian or early Albian). Portugal / Rydin et al. 2006a / Ephedroid seeds have in situ pollen.
Ephedra verticillata Cladera et al. / the Anfiteatro de Tico Formation (Baquero Group), Early Aptian. Argentina / Cladera et al. 2007 / An Ephedroid reproductive shoot has stems with verticillate branches and terminal seed cones. Each cone has two FRUs/seeds.
Ephedrispermum lusitanicum Rydin et al. / Calvaria Member, Figueira da Foz Formation. Early Cretaceous (late Aptian or early Albian). Portugal / Rydin et al. 2006a / Ephedroid seeds have in situ pollen.
Erenia stenoptera Krassilov / Syn.: Callianthus dilae Wang et Zheng in J. Int. Plant Biol., 51: 800. 2009. / the Yixian Formation, western Liaoning of China; the Gurvan-Eren Formation of Mongolia / Krassilov 1982 / Wu (1999) correctly identified the plant from the Yixian Formation but Wang Zheng (2009) erected it as a new genus. This species includes fleshy cones that are bisexual or unisexual. It is quite amazing that the male reproductive units persisted when the bracts got fleshy if the previous reports are accepted (Wang Zheng 2009). Fleshiness is probably an indicator of mature cones.
Friedsellowia gracifolia Löwe et al. / Crato Formation, Araripe Basin, Open air pit south of Nova Olinda near Santana do Cariri, State of Ceará, Brazil / Mohr et al. 2007; Löwe et al. 2013 / A monoecious plant bears both male and female cones. Male cones are terminal to twigs and have many pairs of bracts. Female cones are sessile and sit amidst twigs bearing the male cones, and possess multiple fertile whorls of bracts that are arranged in whorls of four or in pairs of two. Löwe et al. (2013) thought this plant is close to Welwitschia in the female cones bearing multiple whorls of fertile bracts and the leaf venation, however, it is noticeable that there are many other differences.
Gurvanella dictyoptera Krassilov / Syn.: Chaoyangia liangii Duan in Sci. China, 41: 14. 1998; Gurvanella exquisita G. Sun et al., Early Angiosperms and their associated plants from western Liaoning, China, 207. 2001. / Yixian Formation, western Liaoning of China; the Gurvan-Eren Formation of Mongolia. Early Cretaceous. / Krassilov 1982 / This species was first found from Early Cretaceous of Mongolia, but later recorded in the Yixian Formation. Dispersed female cones are common, but reproductive shoots are rare. Krassilov (1982) thought this species might have been living on slopes.
Khitania columnispicata Guo et al. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Guo et al. 2009 / A very compact spike with many circular rings shows affinity to the male cone of Gnetum.
Liaoxia acutiformis Rydin, S.Q. Wu et Friis / Dawangzhangzi Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Rydin et al. 2006b / An Ephedroid reproductive shoot has female cones with 6-12 pairs of bracts and linear leaves with two parallel veins.
Liaoxia changii Rydin, S.Q. Wu et Friis / Syn.: “Eragrosites changii Cao et Wu” in Chin. Sci. Bull. 43: 231. 1998. nom. inval. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Rydin et al. 2006b / An Ephedroid reproductive shoot possesses terminal female cones with 6-10 pairs of bracts. It was merged into Ephedrites cheniae by Guo Wu (2000), but retained as a separate species in Rydin et al. (2006b).
Liaoxia cheniae (S.X. Guo et X.W. Wu) Rydin, S.Q. Wu et Friis / Syn.: Ephedra cheniae (S.X. Guo et X.W. Wu) Liu et al. in Taxon, 57: 578. 2008; Ephedrites cheniae S.X. Guo et X.W. Wu in Acta Palaeontol. Sin. 39: 82. 2000, pro parte / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Rydin et al. 2006b / This is a well-known ephedroid fossil species from the Yixian Formation. Its nomenclature is quite complicated (Yang 2007, 2010). Cyperacites sp. in Krassilov (1982) definitely belongs to this species. This species is an Ephedroid reproductive shoot having female cones with 2-6 pairs of bracts and linear leaves with two parallel veins.
Liaoxia elongata Rydin, S.Q. Wu et Friis / Dawangzhangzi Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Rydin et al. 2006b / An Ephedroid reproductive shoot has female cones with 8-12 pairs of bracts.
Liaoxia jeholensis (Yabe et Endô) Y. Yang et Q. Wang, comb. nov. / Basionym: Potamogeton jeholensis Yabe et Endô in Proceedings of the Imperial Academy, 11(7): 274. Figs. 1-2. 1935.
Syn.: Ranunculus jeholensis (Yabe et Endô) Miki in Bull. Mukogawa 12: S19, 1964. syn. nov. / Yixian Formation, western Liaoning of China / Yabe Endô 1935; Miki 1964 / An Ephedroid reproductive shoot bears opposite and decussate phyllotaxy and terminal female cones. Sun et al. (2001) merged this species with Ephedrites cheniae (as “chenii”) which would have resulted in a nomenclatural change of Ephedrites cheniae into Ephedrites jeholensis because the specific epithet “jeholensis” is earlier than “cheniae”. Here we make a new combination because this species bears reproductive characters different from those of L. cheniae.
Liaoxia longibractea Rydin, S.Q. Wu et Friis / Dawangzhangzi Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Rydin et al. 2006b / An Ephedroid reproductive shoot has female cones with 1-2 pairs of bracts.
Liaoxia robusta Rydin, S.Q. Wu et Friis / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Rydin et al. 2006b / An Ephedroid reproductive shoot has female cones with 4-10 pairs of bracts, and linear leaves probably bearing 3-4 parallel veins.
Priscowelwitschia austroamericana (Dilcher et al.) Dilcher et al. / Syn.: Welwitschiella austroamericana Dilcher et al. in Amer. J. Bot. 92: 1299. 2005, nom. illegit., non Welwitschiella O. Hoffmann, in Engler and Prantl, Nat. Pflanzenfam. 4(5): 390. 1894 (Asteraceae), nec Welwitschiella Engler in Bot. Jahrb. Syst. 26: 416. 1899 (Menispermaceae). / Crato Formation. Late Aptian. Northeastern Brazil. / Dilcher et al. 2005 / A plant is explained as cotyledonary seedlings of Welwitschiaceae, however, shows extreme similarity with fruits of the Tropical Asian Hoppea spp. of Dipterocarpaceae.
Prognetella minuta Krassilov et Bugdaeva / Syn.: Baicarpus gracilis Gang Han et al. in Acta Geol Sin 87: 920. 2013. pro parte, PB21629; B. robusta Gang Han et al., l.c. 921. / the Yixian Formation, western Liaoning of China; the Baisa locality in the upper reaches of the Vitim River, Transbaikalia of Mongolia / Krassilov Bugdaeva 1999 / A reproductive shoot has leaf-like bracts each subtending an axillary sessile female reproductive unit, each leaf/bract is provided with 2 (rarely 4) parallel veins. This species was preserved frequently as detached diaspores.
Prognetella gracilis (Gang Han et al.) Y. Yang et Q. Wang / Basionym: Baicarpus gracilis Gang Han et al. in Acta Geol Sin 87: 920. 2013. pro parte, excl. PB21629. / Jianshangou Bed, Yixian Formation, Early Cretaceous (Barremian-early Aptian?). China / Diaspores were previously described as angiosperms, is actually an early Ephedraceae.
Siphonospermum simplex C. Rydin et E.M. Friis / the Yixian Formation, western Liaoning of China / Rydin Friis 2010 / An Ephedroid reproductive shoot has female reproductive units terminal to twigs and linear leaves with three parallel veins.
Welwitschiophyllum brasiliense Dilcher et al. / Crato Formation. Late Aptian. Northeastern Brazil. / Dilcher et al. 2005 / A Welwitschia-like leaf is lanceolate and has many fine longitudinal parallel veins.
Welwitschiostrobus murili Dilcher et al. / Crato Formation. Late Aptian. Northeastern Brazil. / Dilcher et al. 2005 / A reproductive shoot bears terminal male cones similar to Welwitschia mirabilis.

Doubtful species

1.  Ephedrites guozhongiana G. Sun et S.L. Zheng was described in Sun et al. (2001) from the Yixian Formation. It is definitely not Ephedraceae, but may be related to ferns.

2.  Leongathia elegans Krassilov et al. (1998) is a vegetative shoot from the Lower Cretaceous of Koonwarra Fossil Bed, Victoria, Australia.

3.  Qataniaria noae Krassilov from the Upper Hatira Formation of Makhtesh, Qatan of Israel (Krassilov Schrank 2011) bears vegetative and reproductive characters unlike those of Ephedraceae.

4.  Cearania heterophylla Kunzmann et al. (2009) and Cariria orbiculiconiformis Kunzmann et al. (2011) are two macrofossil species from the Early Cretaceous with uncertain relationships within the Gnetales.