[Taxacom] New genus of early angiosperms (Early Jurassic flowers)
Kenneth Kinman
kinman at hotmail.com
Thu Dec 20 06:36:50 CST 2018
Hi Tony,
Yes, I was initially skeptical when I saw the news reports. But after reading the paper, I have no doubts about them being angiosperms. As for the age, that has been somewhat problematic for some other early Chinese angiosperms. However, a companion paper co-authored by David Winship Taylor agrees that these are angiosperms and almost certainly Early Jurassic. So I am now far more interested in whether they are stem angiosperms or crown angiosperms. Their unique mixture of characteristics is fascinating.
---------------Ken
Weblink to the paper by David Winship Taylor and Hongqi Li:
https://elifesciences.org/articles/43421
________________________________
From: Tony Rees <tonyrees49 at gmail.com>
Sent: Thursday, December 20, 2018 1:39 AM
To: Kenneth Kinman
Cc: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] New genus of early angiosperms (Early Jurassic flowers)
Well, the other claimed "Jurassic angiosperms" have thus far not found much favour with other workers who tend to view them as either not angiosperms, or not Jurassic. So it will be interesting to see how these examples are received... plus these are described as Early Jurassic, not Late, which leaves a rather large gap until the next accepted "flowers" in the Cretaceous somewhere...
Always room for some new fossils and information, though!
Regards - Tony
On Thu, 20 Dec 2018 at 13:32, Kenneth Kinman <kinman at hotmail.com<mailto:kinman at hotmail.com>> wrote:
Dear All,
I didn't plan to post anything further on the origin of angiosperms, but a fascinating new genus of angiosperm was named and described this week (called Nanjinganthus), and it is from the Early Jurassic. Although it is clearly an angiosperm, it's phylogenetic position has not been determined, so it is unclear if it is a stem group angiosperm or a member of the crown group. In any case, it is an exciting development, and here is a weblink to the article (and the abstract is given below):
https://elifesciences.org/articles/38827
Abstract
The origin of angiosperms has been a long-standing botanical debate. The great diversity of angiosperms in the Early Cretaceous makes the Jurassic a promising period in which to anticipate the origins of the angiosperms. Here, based on observations of 264 specimens of 198 individual flowers preserved on 34 slabs in various states and orientations, from the South Xiangshan Formation (Early Jurassic) of China, we describe a fossil flower, Nanjinganthus dendrostyla gen. et sp. nov.. The large number of specimens and various preservations allow for an evidence-based reconstruction of the flower. From the evidence of the combination of an invaginated receptacle and ovarian roof, we infer that the seeds of Nanjinganthus were completely enclosed. Evidence of an actinomorphic flower with a dendroid style, cup-form receptacle, and angiospermy, is consistent with Nanjinganthus being a bona fide angiosperm from the Jurassic, an inference that we hope will re-invigorate research into angiosperm origins. https://doi.org/10.7554/eLife.38827.001
________________________________
From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu<mailto:taxacom-bounces at mailman.nhm.ku.edu>> on behalf of Kenneth Kinman <kinman at hotmail.com<mailto:kinman at hotmail.com>>
Sent: Friday, December 14, 2018 8:43 AM
To: taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>
Subject: [Taxacom] Where (and when) angiosperms originated
Dear All,
I've been studying the literature on angiosperm origins, and there is apparently a very long period of time between the origin of angiosperms and the origin of crown group angiosperms. I have concluded that where angiosperms originated is probably also a totally different place.
Crown group angiosperms probably originated in Gondwana, most likely in Australia since so many basal families occur in the forests of northern Queensland (which in the past were even closer to New Caledonia). However, where the first angiosperms originated is a totally different question. My hypothesis is that the first angiosperms perhaps split from their probable sister group Caytoniales as far away as Laurasia, rather than Gondwana (perhaps in the Permian, if not earlier).
Of course, the larger numbers of records of putative angiosperm pollen (and Caytonia fossils) in Europe and eastern North America could be due to more intensive research in those areas, so an origin in Africa shouldn't be ruled out. What route they took to Australia could depend on when that expansion took place. Papers by Dettmann suggested that they got to Australia through Antarctica. In any case, there is no evidence that angiosperms originated in Australia, but there is plenty of evidence that crown group angiosperms did originate in Australia (far from where the earliest angiosperms originated).
-------------Ken Kinman
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