WFS News: An unexpected noncarpellate epigynous flower from the Jurassic of China

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Idealized reconstruction of Nanjinganthus. 1, branches of dendroid style; 2, dendroid style; 3, sepal; 4, ovarian roof; 5, scale; 6, seed; 7, cup-form receptacle/ovary; 8, bract; 9, petal; 10, unknown organ (staminode?). https://doi.org/10.7554/eLife.38827.019

Idealized reconstruction of Nanjinganthus.
1, branches of dendroid style; 2, dendroid style; 3, sepal; 4, ovarian roof; 5, scale; 6, seed; 7, cup-form receptacle/ovary; 8, bract; 9, petal; 10, unknown organ (staminode?).
https://doi.org/10.7554/eLife.38827.019

Despite the importance of, the great interest in and intensive effort spent on investigating angiosperms, a controversy remains as to when and how this group came into existence. Since the time of Darwin, some scholars have proposed that angiosperms existed before the Cretaceous (Smith et al., 2010Clarke et al., 2011Zeng et al., 2014Buggs, 2017), although the conclusion ‘there are no reliable records of angiosperms from pre-Cretaceous rocks’ made almost 60 years (Scott et al., 1960) seemed to be recently re-confirmed (Herendeen et al., 2017). Such uncertainty makes answers to many questions about the phylogeny and systematics of angiosperms tentative. Some reports of early angiosperms (i.e., Monetianthus (Friis et al., 2001)) are based on a single specimen, which restricts further testing and confirming. Better and more specimens of early age and with features unique to angiosperms are highly sought-after to test related evolutionary hypotheses. Here, we report an unusual actinomorphic flower, Nanjinganthus gen. nov., from the Lower Jurassic based on the observations of 264 specimens of 198 individual flowers on 34 slabs preserved in various orientations and states (Supplementary file 1). The abundance of specimens allowed us to dissect some of them, thus demonstrate and recognize a cup-form receptacle, ovarian roof, and enclosed ovules/seeds in Nanjinganthus. These features are consistent with the inference that Nanjinganthus is an angiosperm. The origin of angiosperms has long been an academic ‘headache’ for many botanists, and we think that Nanjinganthus will shed a new light on this subject.

Siltstone slabs bearing Nanjinganthus. All bars are 1 cm long. (A) Six flowers (1-6) on the same slab, and an associated triangular leaflet with parallel venation. PB22227. (B) Several flowers on the same slab. 1–3 are shown in detail in Figures 2f and 6d,e. PB22226. (C) Several flowers (1-8) on the same slab and the associated Nilssonia parabrevis (top). PB22220. (D) Several flowers (1-6) on the same slab. 1–3 are shown in detail in Figures 2h and 3a–c. PB22224. (E) Many flowers on the same slab. Some of the numbered ones are shown in detail in later figures. PB22222a. (F) A slab with numerous flowers. PB22221. (G) A slab almost fully covered with flowers. PB22228.

Siltstone slabs bearing Nanjinganthus. All bars are 1 cm long. (A) Six flowers (1-6) on the same slab, and an associated triangular leaflet with parallel venation. PB22227. (B) Several flowers on the same slab. 1–3 are shown in detail in Figures 2f and 6d,e. PB22226. (C) Several flowers (1-8) on the same slab and the associated Nilssonia parabrevis (top). PB22220. (D) Several flowers (1-6) on the same slab. 1–3 are shown in detail in Figures 2h and 3a–c. PB22224. (E) Many flowers on the same slab. Some of the numbered ones are shown in detail in later figures. PB22222a. (F) A slab with numerous flowers. PB22221. (G) A slab almost fully covered with flowers. PB22228.https://doi.org/10.7554/eLife.38827.005

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

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