There have an age old relationship
between flower and birds. To proved this statement Scientists of the
Senckenberg Research Institute in Frankfurt have described the oldest known
fossil of a pollinating bird. The well-preserved stomach contents contained
pollen from various flowering plants. This indicates that the relationship
between birds and flowers dates back at least 47 million years. The fossil
comes from the well-known fossil site "Messel Pit."
Details
They fly from flower to flower, and with their long, slender bills they transfer the pollen required for the plants' reproduction. Particularly in the tropics and subtropics, birds, besides insects, serve as the most important pollinators.
"While this process is well
known and understood in the present, geological history has offered very little
evidence of pollination through birds," says Dr. Gerald Mayr, head of the
Ornithological Section at the Senckenberg Research Institute in Frankfurt. He
adds, "there have been occasional hints, such as characteristic bill
shapes, that nectarivorous birds occurred in the past, but, so far, there
existed no conclusive evidence."
Now, however, the ornithologist from
Frankfurt and his colleague, paleobotanist Dr. Volker Wilde, have found this
evidence. In the well-preserved stomach contents of a fossil bird unearthed in
the Messel Pit, the scientists discovered fossilized pollen grains.
"This is another discovery that
underlines the unique significance of the Messel fossil site," exclaims a
delighted Dr. Wilde. "Not only does the presence of pollen offer direct
evidence of the bird's feeding habits, but it shows that birds already visited
flowers as long as 47 million years ago!"
Fossil evidence for the existence of
pollinating insects dates back to the Cretaceous period. Until now, however,
there had been no information at what time pollination through vertebrates, and
birds in particular, came into existence. To date, the oldest indication of an
avian pollinator came from the early Oligocene, about 30 million years ago.
"But this hummingbird fossil only offers indirect evidence of the
existence of nectarivorous birds," explains Mayr. "Thanks to the
excellent state of preservation of the Messel bird, we were able to identify
two different types of pollen, which is the first conclusive proof of
nectarivory."
Large numbers of differently sized
pollen grains were found in the stomach contents of the completely preserved
avian fossil. "Along with the bird's skeletal anatomy, this indicates that
we indeed have the fossil of a nectarivorous bird" explains Wilde.
And the spectacular discovery also
suggests another conclusion: If a pollinating bird lived as much as 47 million
years ago, it must be assumed that some representatives of the flora at that
time had already adapted to this mode of pollination.
"To date, there are no fossil
plants from this geological era that offer proof of the existence of
ornithophily -- i.e., the pollination of flowers through birds," adds
paleobotanist Wilde.
"However, the characteristic
traits of bird-pollinated plants, such as red flowers or a lack of scent, do
not fossilize," elaborates Mayr. This lends an even greater importance to
discoveries such as the Messel bird to understand the interactions between
birds and flowers through geological time.
I hope you like this article.
0 comments:
Post a Comment