Tropidogyne euthystyla sp. nov., a new small-flowered addition to the genus from mid-Cretaceous Myanmar amber

  • George O. Poinar, Jr. Department of Integrative Biology, Oregon State University
  • Kenton L. Chambers Department of Botany and Plant Pathology, Oregon State University
  • Fernando E. Vega Sustainable Perennial Crops Laboratory, U. S. Department of Agriculture, Agricultural Research Service

Abstract

Tropidogyne euthystyla, described here, is the fourth species of this fossil genus to have been reported from amber deposits in northern Myanmar. The species are alike in features of the calyx, the shape and venation of the inferior ovary, and the absence of petals. They differ in the number and form of the styles, the lobing of the epigynous disc, and whether the flowers are apparently bisexual or unisexual. In the one species for which several flowers are available for study, T. pentaptera, floral diameters vary from 3.5 to 5.0 mm. The present species, known only from a single flower, is the smallest in the genus, with a floral diameter of only 2 mm. It differs from the 3 previously described species in having 2 stout, erect styles bearing a terminal stigma, whereas the other species have 2 or 3 short or long, arching styles that are decurrently stigmatic along the adaxial surface.

References

Barnes, R.W. & R.S. Hill. 1999. Ceratopetalum fruits from Australian Cainozoic sediments and their significance for petal evolution in the genus. Austral. Syst. Bot. 112:635–645.
Barnes, R.W. & A.C. Rozefelds. 2000. Comparative morphology of Anodopetalum (Cunoniaceae). Austral. Syst. Bot. 13:267–282.
Bradford, J.C., H.C.F. Hopkins, & R.W. Barnes. 2004. Cunoniaceae. In: K. Kubitzki, ed. The families and genera of vascular plants. Springer Verlag, Berlin, Germany. 6:91–111.
Chambers, K.L. & G.O. Poinar, JR. 2020. Thymolepis toxandra gen. et sp. nov., a mid-Cretaceous fossil flower with horseshoe-shaped anthers. J. Bot. Res. Inst. Texas 14:57–64.
Chambers, K.L., G.O. Poinar, JR., & R. Buckley. 2010. Tropidogyne, a new genus of Early Cretaceous eudicots (Angiospermae) from Burmese amber. Novon 20:23–29.
Crepet, W.L., K.C. Nixon, D. Grimaldi, & M. Riccio. 2016. A mosaic Lauralean flower from the Early Cretaceous of Myanmar. Amer. J. Bot. 103:290–297.
Cruickshank, R.D. & K. Ko. 2003. Geology of an amber locality in the Hukawng Valley, northern Myanmar. J. Asian Earth Sci. 21:441–455.
Dickison, W.C. 1989. Comparisons of primitive Rosidae and Hamamelidae. In: P.R. Crane & S. Blackmore, eds. Evolution, systematics and fossil history of the Hamamelidae. Clarendon Press, Oxford, UK. 1:47–73.
Gandolfo, M.S. & E.J. Hermsen. 2017. Ceratopetalum (Cunoniaceae) fruits of Australasian affinity from the early Eocene Laguna del Hunco flora, Patagonia, Argentina. Ann. Bot. 119:507–516.
Hopkins, H.C.F. 2018. The taxonomy and morphology of Schizomeria (Cunoniaceae) in New Guinea, the Moluccas, and the Solomon Islands, with notes on seed dispersal and uses throughout the genus. Kew Bull. 73:11–21.
Hopkins, H.C.F., A.C. Rozefelds, & Y. Pillon. 2013. Karrabina gen. nov. (Cunoniaceae), for the Australian species previously placed in Geissois, and a synopsis of genera in the tribe Geissoieae. Austral. Syst. Bot. 26:167–185.
Liu, Z-J., D. Huang, C. CAI, & Z. Wang. 2018. The core eudicot boom registered in Myanmar amber. Sci. Rep. 8:16765.
Pillon, Y., H.C.F. Hopkins, & J.C. Bradford. 2008. Two new species of Cunonia (Cunoniaceae) from New Caledonia. Kew. Bull. 63:419–431.
Poinar, G.O., JR. & K.L. Chambers. 2017. Tropidogyne pentaptera sp. nov., a new mid-Cretaceous fossil angiosperm flower in Burmese amber. Palaeodiversity 10:135–140.
Poinar, G.O., JR. & K.L. Chambers. 2018. Endobeuthos paleosum gen. et sp. nov., fossil flowers of uncertain affinity from mid-Cretaceous Myanmar amber. J. Bot. Res. Inst. Texas 12:133–139.
Poinar, G.O., JR. & K.L. Chambers. 2019a. Dispariflora robertae gen. et sp. nov., a mid-Cretaceous flower of possible Lauralean affinity from Myanmar amber. J. Bot. Res. Inst. Texas 13:173–183.
Poinar, G.O., JR. & K.L. Chambers. 2019b. Tropidogyne lobodisca sp. nov., a third species of the genus from mid-Cretaceous Myanmar amber. J. Bot. Res. Inst. Texas 13:461–466.
Poinar, G.O., JR. & K.L. Chambers. 2020a. Dasykothon leptomiscus gen. et sp. nov., a fossil flower of possible Lauralean affinity from Myanmar amber. J. Bot. Res. Inst. Texas 14:65–71.
Poinar, G.O., JR. & K.L. Chambers. 2020b. Chainandra zeugostylus gen. et sp. nov., a mid-Cretaceous amber fossil with sagittate anthers opening widely at maturity. J. Bot. Res. Inst. Texas 14:357–372.
Poinar, G.O., JR. & S. Ellenberger. 2020. Burmese amber fossils, mining, sales and profits. Geoconserv. Res. 3:12–16.
Poinar, G.O., JR., R. Buckley, & A. Brown. 2006. The secrets of Burmese amber. Mid Amer. Paleontol. Soc. Digest 29:20–29.
Poinar, G.O., JR., K.L. Chambers, & J. Wunderlich. 2013. Micropetasos, a new genus of angiosperms from mid-Cretaceous Burmese amber. J. Bot. Res. Inst. Texas 7:745–750.
Poinar, G.O., JR., K.L. Chambers, U.T. Iwaniec, & F.E. Vega. 2020. Valviloculus pleristaminis gen. et sp. nov., a Lauralean fossil flower with valvate anthers from mid-Cretaceous Myanmar amber. J. Bot. Res. Inst. Texas 14:359–366.
Poinar, G.O., JR., G.J.B. Lambert, & Y. Wu. 2007. Araucarian source of fossiliferous Burmese amber: Spectroscopic and anatomical evidence. J. Bot. Res. Inst. Texas 1:449–455.
Rogers, Z.S. 2002. A new species of Weinmannia (Cunoniaceae: Cunonieae) from southern Ecuador. Novon 12:249–252.
Rozefelds, A.C. & R.W. Barnes. 2002. The systematic and biogeographical relationships of Ceratopetalum (Cunoniaceae) in Australia and New Zealand. Int. J. Pl. Sci. 163:651–673.
Rozefelds, A.C. & B. Pellow. 2011. A taxonomic revision of Pseudoweinmannia Engl. (Cunoniaceae: Geissoieae). Austrobaileya 8:252–266.
Rozefelds, A.C., R.W. Barnes, & B. Pellow. 2001. A new species and comparative morphology of Vesselowskya (Cunoniaceae). Austral. Syst. Bot. 14:175–192.
Shi, G., D.A. Grimaldi, G.E. Harlow, J. Wang, M. Yang, W. Lei, Q. Li, & X. Li. 2012. Age constraint on Burmese amber based on U-Pb dating of zircons. Cretaceous Res. 37:155–163.
Sokol, J. 2019. Troubled treasure. Science 364:722–729.
Published
2021-07-23
How to Cite
Poinar, Jr., G. O., Chambers, K. L., & Vega, F. E. (2021). Tropidogyne euthystyla sp. nov., a new small-flowered addition to the genus from mid-Cretaceous Myanmar amber. Journal of the Botanical Research Institute of Texas, 15(1), 113-119. https://doi.org/10.17348/jbrit.v15.i1.1053

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