Monday, November 09, 2009

Insect Pollination Before Angiosperms

A Probable Pollination Mode Before Angiosperms: Eurasian, Long-Proboscid Scorpionflies

1. Dong Ren (a)
2. Conrad C. Labandeira (b,c,*)
3. Jorge A. Santiago-Blay (b,d)
4. Alexandr Rasnitsyn (e,f)
5. ChungKun Shih (a)
6. Alexei Bashkuev (e)
7. M. Amelia V. Logan (g)
8. Carol L. Hotton (b,h)
9. David Dilcher (b,i)

a College of Life Sciences, Capital Normal University, Beijing 100048, China.

b Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.

c Department of Entomology, University of Maryland, College Park, MD 20742, USA.

d Department of Biology, Gallaudet University, Washington, DC 20003, USA.

e Paleontological Institute, Russian Academy of Sciences, Moscow 117997, Russia.

f Department of Palaeontology, Natural History Museum, London SW7 5BD, UK.

g Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.

h National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20892, USA.

i Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.

* To whom correspondence should be addressed. E-mail: labandec@si.edu

Abstract:

The head and mouthpart structures of 11 species of Eurasian scorpionflies represent three extinct and closely related families during a 62-million-year interval from the late Middle Jurassic to the late Early Cretaceous. These taxa had elongate, siphonate (tubular) proboscides and fed on ovular secretions of extinct gymnosperms. Five potential ovulate host-plant taxa co-occur with these insects: a seed fern, conifer, ginkgoopsid, pentoxylalean, and gnetalean. The presence of scorpionfly taxa suggests that siphonate proboscides fed on gymnosperm pollination drops and likely engaged in pollination mutualisms with gymnosperms during the mid-Mesozoic, long before the similar and independent coevolution of nectar-feeding flies, moths, and beetles on angiosperms. All three scorpionfly families became extinct during the later Early Cretaceous, coincident with global gymnosperm-to-angiosperm turnover.


Interesting...

1 comment:

Anonymous said...

Maybe there were several groups of insect pollinators before the rise of angiosperms, but they all died out when their host species were out-competed by angiosperms (why, I don't know).