Fig 1.
Photographs of sterile pinnae of Weichselia reticulata collected from Las Hoyas fossil site.
A, large isolated fragment of primary pinna with complete secondary pinna (MCCM-LH 18059B) scale bar = 5cm. B, primary pinna template (MCCM-LH 2859) scale bar = 10cm. C, isolated fragment of secondary pinna (MCCM-LH 16633) scale bar = 1cm. D-E, nearly complete juvenile frond (MCCM-LH 17327), D whole fossil preserved, E detail, scale bars = 10cm. F, detail of basal zone of secondary pinna (MCCM-LH 32554) scale bar = 1cm. G, close-up of a primary pinna impression (MCCM-LH 37758), scale bar = 0.5cm. H, isolated charred fragment of primary pinna (MCCM-LH 30067) scale bar = 1 cm.
Fig 2.
Criteria used for the metric analysis and partition of the pinna in zones.
The zones are labelled with the letters B, Basal, M, Middle, and A, Apical. Numbers stand for the measurements taken at the primary pinna level (PP) and the secondary pinna level (SP). (1) IA-PP, secondary pinna insertion angle; (2) DBP-PP, distance between secondary pinnae; (3) FSL, length of the first segment of the secondary pinna; (4) TL-PP, total length of the secondary pinna; (5) RW, width of the primary rachis; (6) IA-SP, pinnule insertion angle; (7) DBP-SP, distance between pinnules; and (8) TL-SP, total length of the pinnule.
Table 1.
Ratio calculations for primary and secondary pinna.
Fig 3.
Relocation of the fossil fragments for the primary pinna.
The relocation of Weischelia fragments is based on: A, the insertion angle (IA), and B, the distance between pinnae (DBP). A, graphs representing the insertion angle (IA) of all the primary pinnae studied. Left plot shows the IA of each secondary pinna; the solid line represents the template (MCCM-LH 2958), and coloured dots represent each specimen. Right plot shows the IA mean (dotted line) of all specimens except for the template, solid line represents the insertion angle of secondary pinnae of the template. IA in degrees. B, depicts the limits for the positive and negative values of DBP along the primary pinna.
Fig 4.
Metrics of the primary pinna of W. reticulata.
A, mean and standard deviation of the measurements rachis width (RW), distance between secondary pinnae (DBP-PP), and first segment length (FSL) for each zone of the primary pinna. B, mean and standard deviation of the insertion angle (IA-PP) of mature pinnae and of specimen MCCM-LH 17327 for each zone of the primary pinna. C, mean distance between secondary pinnae of both sides (left and right) of the primary pinna MCCM-LH 17327–1 for each part of the primary pinna. D, Branching ratio of MCCM-LH 2958 (dots) represented by the pair (x = DBP-PP, y = FSL); and MCCM-LH 17327 (stars), represented by the pair (x = DBP-PP, y = TL-PP). FSL and TL-PP have a strong correlation (Pearson correlation = 0.597, p-value = 0.00). All linear measurements in cms.
Fig 5.
Box and whiskers graph of the interval ratio.
Comparison between the mature primary pinnae and the juvenile frond MCCM-LH 17327.
Fig 6.
A, The PCA of the primary pinnae includes the juvenile frond (MCCM-LH 17327, stars in the graphic), the adult template (MCCM-LH 2958), and isolated fragments (dots in the graphic). B, Deformation grid of the superposition of the adult specimen MCCM-LH 2958 over the mean of the primary pinnae of the juvenile frond using MorphoJ. The maximum variation corresponds to zone M. The lateral variation of the rachis observed on the grid is an artefact due to the one on one comparison of only one side of the pinnae. The colour code is the same as in Fig 3.
Table 2.
PCA loadings for PCA of the primary pinna level excluding the variable RW from the analysis.
Fig 7.
Metrics of the secondary pinna of W. reticulata.
A, mean and standard deviation of the total length of the pinnule (TL-SP) and the distance between pinnules (DBP-SP) at each zone of the secondary pinna. B, mean pinnule insertion angle for each zone of the secondary pinna. C, schematic drawing of the change in pinnule morphology and size throughout the secondary pinna. D, branching ratio of specimen MCCM-LH 18059–19, mean and standard deviation for each zone of the secondary pinna are marked as coloured zones in the graph. All linear measurements in cm.
Fig 8.
PCA of Weichselia and of extant fern pinnae.
A. Weichselia reticulata. B. Matonia pectinta. C. Angiopteris evecta. D-E. Sphaeropteris cooperi primary and secondary pinnae respectively. F. Woodwardia unigemmata. Scale bars = 1cm.
Fig 9.
Schematic drawing of the basiplastic growth in the frond of W. reticulata.
Fig 10.
Sinuous rachis in extant ferns.
A, S morphology in Polistichum setiferum (Forssk.) Moore ex Woynar. B, Sinuous rachis in Sphaeropteris cooperi (F. Muell) R.M Tryon. C, Plagiotropic Adiantum L. with sinuous rachis.