Salopella Edwards and Richardson, 1974

McSweeney, Fearghus R., Shimeta, Jeff & Buckeridge, John St J. S., 2021, Early land plants from the Lower Devonian of central Victoria, Australia, including a new species of Salopella, Memoirs of Museum Victoria 80, pp. 193-205 : 201

Genus. Salopella Edwards and Richardson, 1974

Salopella laidae McSweeney, Shimeta and Buckeridge , sp. nov. ( fig. 5A, B , fig. 6D )

Salopella australis Tims and Chambers (1984 : pl. 32, fig. 3 , text-fig. 2C )

Diagnosis. Plant at least 55 mm long, tuft branching architecture, with sporangia all reaching the same height, with naked dichotomously synchronous branched axes up to 3.2 mm wide basally and 1.3 mm below sporangia. Axial width decreases after each dichotomy. Isotomous branching angles small, 30°–40° for the ultimate dichotomies and 15°–50° for basal dichotomies. At least two orders of branching. Branching 10.0–14.0 mm below sporangia. Eight sporangia, elongate subfusiform 9.7–11.0 mm high and up to 2.5 mm at widest section in mid region, and wider than subtending axes, obtuse apices.

Etymology. Named for Mrs Peg Laid who kindly gave permission to collect fossil specimens from her property on Ghin Ghin Road, Yea.

Holotype. NMV P50011.1 and NMV P50011.2 , part and counterpart respectively, figured by Tims and Chambers, 1984: pl. 32, fig. 3 and text-fig. 2 C

Locality. Location 4, Brackley’s cutting ( Harris and Thomas, 1941) Limestone Road, 2 km southeast of Yea. Note: exposure referred to as locality 62 in Couper (1965). 37° 12.38' S, 145° 25.39' E.

Stratigraphy and age. Location 4 ( Harris and Thomas, 1941: 303) Yea Formation ( Garratt 1978), Lower Devonian (Pragian; Edwards et al., 1997; Rickards, 2000; Rickards and Garratt, 1990).

Figures

Figure 2. Salopella australis displaying parallel parent axes dichotomising into much shorter daughter axes that are terminated with elongate sporangia, delineated with a constriction just above dark sporogeneous region. All from Wilson Creek Shale on Frenchmans Spur track, 10 km west of Matlock.A, erect parent axes parallel to each other, dichotomising into two elongate sporangia from Wilson Creek Shale. Re-photographed here; originally published in Tims and Chambers (1984: pl. 32, fig. 4) and Tims (1980: fig. 4.1.9). Specimen NMV P50014. B, forked dichotomy terminated by sporangia from Wilson Creek Shale. And to the right hand side of the forked axis is another long axis, which based on its orientation may also be part of the same plant. Constriction at arrow, lower arrow at dichotomy and double arrow at two aligned axes. Specimen NMV P33219. C, close-up of fructification in A, sporangia barely extend beyond the confines of their subtending axes, with slight constriction present above sporogeneous region (at arrow). Specimen NMV P50014. D, E, holotype, part and counterpart. On part, constriction at arrow in sporangium. On counterpart, both parent axes are parallel to each other (at dotted arrow). Re-photographed here, originally published in Tims and Chambers (1984: pl. 32, figs. 1, 2). Specimens NMV P50008.1 and NMV P50008.2, respectively. F, Gen. et sp. indet. – short daughter axes terminated in elongate sporangia. The cortex may be absent from subtending axes, with only the central line visible. The lack of cortex prevents assigning to S. australis as width of subtending axis to sporangial width is required. Originally photographed by Tims (1980: fig. 4.1.13). Specimen NMV P50010.2. G, S. australis, with two short daughter axes, with constriction at arrow of the sporangium, which is the same width as its subtending axis. Specimen NMV P202886.

Figure 3. Salopella caespitosa (holotype) from Wilson Creek Shale on Frenchmans Spur track, 10 km west of Matlock. A, B, part (NMV P202987.1) and counterpart (NMV P202987.2), respectively; numbering follows Tims and Chambers (1984, pl. 33, fig. 1). Counterpart images are reversed to be in the same orientation as the part specimen. A, on right-hand side of part specimen, double isotomous dichotomies lead to sporangia one–seven. Note, at the arrows, there is perpendicular branching that is suggestive of a rhizomatous system. C, sporangium 12; at the arrow there is another axis that is terminated in a sporangium that is partially visible. Specimen NMV P202987.1. D–F, Evidence of a slight constriction beneath sporangia at arrows. D, sporangia eight and nine (on the left). Widest part of each sporangium occurring approximately midway along their length. Note, rephotographed; originally published in Tims and Chambers (1984: pl. 34, fig. 3). Specimen NMV P202987.1. E, sporangium 22 is c. 4.06 mm long and 1.4 mm wide. The axis decreases from 1.2 mm proximally to 0.5 mm just beneath the sporangium. Specimen = NMV P202987.2. F, sporangia four (right) and five, both sporangia are slightly wider in the lower quarter of each sporangia. Specimen = NMV P202987.2. G, sporangium 22, appears to be two immature sporangia juxtaposed. At arrow, the apex (rounded) of the smaller fusiform sporangium is apparent. Specimen NMV P202987.1. H, sporangium two, lower arrow at walls surrounding presumed oval sporogeneous area, which reaches approximately halfway the length of the sporangium to the upper arrow. Specimen NMV P202987.1. I, sporangium 13, arrows at walls surrounding sporangeneous area and upper arrow showing extent of oval sporogenous body. The walls does not recombine apically like in sporangium two, suggesting it may have been crushed, or hidden, beneath the matrix. Rephotographed; originally figured by Tims and Chambers (1984: pl. 33, fig. 3). Specimen NMV P202987.2.

Figure 5. Salopella laidae sp. nov. (holotype) NMV P50011.1 and NMV P50011.2, part and counterpart, respectively, with counterpart reversed to be in the same orientation as part specimen. From location 4 (Brackley’s cutting) on Limestone Road, Yea. A, double isotomous dichotomy visible, terminated with eight elongate sporangia, five visible. At lower arrow central line and at F, folding of tissue. On sporangium seven?sporogenous region highlighted. Rephotographed; originally figured by Tims and Chambers, 1984: pl. 32, fig. 3 and text-fig. 2C. B, arrow at daughter axis missing on part present.

Figure 6. Line-drawings of Victorian early land plants with longer than wider sporangia. A, Salopella australis from Wilson Creek Shale on Frenchmans Spur track, near Matlock. Specimen NMV P50014.B, Gen. et sp. indet. from Limestone Road, Yea. Originally placed in S. australis but branching architecture clearly differs. Specimen NMV P157323. C, Salopella laidae sp. nov. from Limestone Road, Yea. NMV P50011. D, Salopella caespitosa (holotype) from Wilson Creek Shale on Frenchmans Spur track, near Matlock. Specimen NMV P202987. E, Salopella caespitosa from Ghin Ghin Road, Yea. Specimen NMV P235941.