The flowers that bloom in the Triassic, tra-la
Posted: Wed Oct 02, 2013 1:00 pm
http://www.sciencerecorder.com/news/flowers-evolved-100-million-years-earlier-than-thought-plant-pollen-fossils-reveal/ wrote:
Flowers evolved 100 million years earlier than thought, plant pollen fossils reveal
Science Recorder | Jonathan Marker | October 02, 2013
<<An October 1 news release from the University of Zurich, Switzerland, announced the discovery of plant-like pollens that are over 100 million years older than the 140 million year-old uninterrupted sequence of fossilized pollen from flowers. It is around this time in the Early Cretaceous that scientists generally believe that flowering plants first evolved. However, the latest study documents flowering plant-like pollen that may have originated in the Early Triassic, some 252 to 247 million years ago.
- [b][color=#0000FF][size=115]Flowering plants evolved from the extinct relatives of conifers, ginkgos, cycads, and seed ferns. The most ancient flowering plant fossils known are pollen grains. These small, hearty, and plentiful remnants of ancient flowers fossilize more than other parts.[/size][/color][/b]
Although a considerable number of studies have attempted to estimate the age of flowering plants from molecular data, no consensus has been reached thus far. Generally, depending on the dataset and method of analysis, estimates range from the Triassic to the Cretaceous.
Because very ancient fossils did not exist for flowering plants, molecular estimates could not be “anchored.” ”That is why the present finding of flower-like pollen from the Triassic is significant,” said Professor Peter Hochuli, of the University of Zurich.
Peter Hochuli and Susanne Feist-Burkhardt from Paleontological Institute and Museum, University of Zürich, analyzed two drilling cores from Weiach and Leuggern in northern Switzerland, and subsequently discovered pollen grains that bear a resemblance to fossil pollen from the earliest known flowering plants. Using a technique called Confocal Laser Scanning Microscopy, Hochuli and Feist-Burkhardt obtained high-resolution images across three dimensions of six different types of pollen.
Hochuli and Feist-Burkhardt documented different, but clearly related flowering-plant-like pollen from the Middle Triassic in cores from the Barents Sea, south of Spitsbergen, in a study conducted in 2004. The samples analyzed in the newest study came from a location that is 3000 km south of the previous site. “We believe that even highly cautious scientists will now be convinced that flowering plants evolved long before the Cretaceous,” said Hochuli.
A number of questions abound regarding the appearance of these ancient flowering plants. During the Middle Triassic, both the Barents Sea and Switzerland were located in the subtropics; however, the area of Switzerland was much drier than the region of the Barents Sea. To scientists, this implies that the plants had a broad ecological range. In addition, the pollen’s structure suggests that insects pollinated the plants. The most likely candidates for consideration were beetles, for the reason that bees would not evolve for another 100 million years.
The results of the study appear in the latest issue of Frontiers in Plant Science, in an article entitled, “Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland).”>>