Fossil flowers of Lachnociona camptostylus sp. nov., a second record for the genus in 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

Abstract

Two flowers embedded in a single block of amber from Myanmar are here proposed as a second species of the previously described fossil genus Lachnociona. The mid-Cretaceous age of the fossils was earlier established through paleontological and U-Pb isotope dating methods. Because they lie within millimeters of each other in the amber, the flowers are assumed to have come from the same parent plant. One flower is hermaphrodite while the other is functionally pistillate. They differ by the number of styles—4 in the perfect flower and 5 in the unisexual one—and most notably by the presence, in the perfect flower, of 10 conspicuous nectar glands forming a disc above the whorl of stamens. The pistillate flower has no such glands. In the new species, the arched styles are widely divergent and the ovary is fully inferior, while in the earlier-described Lachnociona terriae, the flower is functionally pistillate, with styles that are erect and connivent or connate. It could not be determined whether the ovary is superior or half-inferior. The best-preserved anther in the perfect flower of L. camptostylus resembles, in its dorsal filament attachment and hooked filament tip, a vestigial anther present in the flower of L. terriae. Pollen of the new species is tri- or tetracolpate. As proposed in the previous paper, the genus may have participated in the early diversification of the rosid clade of eudicots. 

References

Bradford, J.C., H.C. Fortune Hopkins, & R.W. Barnes. 2004. Cunoniaceae. In: K. Kubitzki, ed. The families and genera of vascular plants. VI. Flowering plants—Dicotyledons. Springer-Verlag, Berlin. Pp. 91–111.

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.

Cohen, K.M., S. Finney, & P.L. Gibbard. 2013. International Chronostratigraphic Chart. International Commission on Stratigraphy.

Cruickshank, R.D. & K. Ko. 2003. Geology of an amber locality in the Hukawng Valley, northern Myanmar. J. Asian Earth Sci. 21:441–455.

Friis, E.M. 1990. Silvianthemum suecicum gen. et sp. nov., a new Saxifragalean flower from the Late Cretaceous of Sweden. Biol. Skrift. 36:5–35.

Friis, E.M. & A. Skarby. 1982. Scandianthus gen. nov., angiosperm flowers of Saxifragalean affinity from the Upper Cretaceous of southern Sweden. Ann. Bot. 50:569–583.

Friis, E.M., K.R. Pedersen, & P.R. Crane. 2006. Cretaceous angiosperm flowers: Innovation and evolution in plant reproduction. Paleogeog. Paleoclimat. Paleoecol. 232:251–293.

Friis, E.M., P.R. Crane, & K.R. Pedersen. 2011. Early flowers and angiosperm evolution. Cambridge Univ. Press, Cambridge, UK. 585 pp.

Hermsen, E.J., M.A. Gandolfo, K.C. Nixon, & W.L. Crepet. 2003. Divisestylus gen. nov. (aff. Iteaceae), a fossil saxifrage from the Late Cretaceous of New Jersey, USA. Amer. J. Bot. 90:1373–1388.

Melchior, H. 1964. Engler’s Syllabus der Pflanzenfamilien. Band II, Auflage 12.

Orozco, C.I. 2002. A study of floral morphology in Brunellia Ruiz & Pavón (Brunelliaceae, Oxalidales). Academia Colombiana de Ciencias, Bogota, Colombia.

Poinar, G.O., Jr. 2004. Programinis burmitis gen. et sp. nov., and P. laminatus sp. nov., early Cretaceous grass-like monocots in Burmese amber. Austral. Syst. Bot. 17:497–504.

Poinar, G.O., Jr. 2017. A mid-Cretaceous Lauraceae flower, Cascolaurus burmitis gen. et sp. nov., in Myanmar amber. Cretac. Res. 71:96–101.

Poinar, G.O., Jr. 2018. Burmese amber: Evidence of Gondwanan origin and Cretaceous dispersion. Hist. Biol. 2018:1–6.

Poinar, G.O., Jr. & K.L. Chambers. 2005. Palaeoanthella huangii gen. and sp. nov., an Early Cretaceous flower (Angiospermae) in Burmese amber. Sida 21:2087–2092.

Poinar, G.O., Jr. & K.L. Chambers. 2017. Tropidogyne pentaptera sp. nov., a new mid-Cretaceous fossil angiosperm flower in Burmese amber. Paleodiversity 10:135–140.

Poinar, G.O., Jr. & K.L. CHAMBERS. 2018a. Endobeuthos paleosum gen. et sp. nov., fossil flowers of uncertain affinity from mid-Cretaceous Myanmar amber. J. Bot. Res. Inst. Texas, in press.

Poinar, G.O., Jr. & K.L. CHAMBERS. 2018b. Setitheca lativalva gen. et sp. nov., a Lauralian fossil flower from mid-Cretaceous Myanmar amber. J. Bot. Res. Inst. Texas, submitted.

Poinar, G.O., Jr., R. Buckley, & A. Brown. 2005. The secrets of Burmese amber. Mid Amer. Paleontol. Soc. 29:20–29.

Poinar, G.O., Jr., K.L. Chambers, & R. Buckley. 2007a. Eoëpigynia burmensis gen. and sp. nov., an Early Cretaceous eudicot flower (Angiospermae) in Burmese amber. J. Bot. Res. Inst. Texas 1:91–96.

Poinar, G.O., Jr., G.J.B. Lambert, & Y. Wu. 2007b. Araucarian source of fossiliferous Burmese amber: Spectroscopic and anatomical evidence. J. Bot. Res. Inst. Texas 1:449–455.

Poinar, G.O., Jr., K.L. Chambers, & R. Buckley. 2008. An Early Cretaceous angiosperm fossil of possible significance in rosid floral diversification. J. Bot. Res. Inst. Texas 2:1183–1192.

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., R. Buckley, & H. Chen. 2016. A primitive mid-Cretaceous angiosperm flower, Antiquifloris latifibris gen. et sp. nov., in Myanmar amber. J. Bot. Res. Inst. Texas 10:55–62.

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.

Schönenberger, J., E.M. Friis, M.L. Matthews, & P.K. Endress. 2001. Cunoniaceae in the Cretaceous of Europe: Evidence from fossil flowers. Ann. Bot. 88:423–427.

Schönenberger, J. & M. von Balthazar. 2006. Reproductive structures and phylogenetic framework of the rosids—progress and prospects. Pl. Syst. Evol. 260:87–106.

Published
2018-11-20
How to Cite
Poinar, Jr., G. O., & Chambers, K. L. (2018). Fossil flowers of Lachnociona camptostylus sp. nov., a second record for the genus in mid-Cretaceous Myanmar Amber. Journal of the Botanical Research Institute of Texas, 12(2), 655-666. Retrieved from https://journals.brit.org/jbrit/article/view/966

Most read articles by the same author(s)

1 2 > >>