[Taxacom] New genus of early angiosperms (Early Jurassic flowers)

[Kenneth Kinman]

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

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From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of Kenneth Kinman <kinman at hotmail.com>
Sent: Friday, December 14, 2018 8:43 AM
To: 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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