144 



J.B. RICHARDSON, R.M. RODRIGUEZ AND S.J.E. SUTHERLAND 



becoming sinuous, and less distinct, poleward. Trilete sutures +/- 

 equal the spore radius or slightly less, accompanied by raised, often 

 darkened areas, tapering towards the amb. A wider thinner proximal 

 triangular area reaches c. 4/5ths of the spore radius and inter-radially 

 often reaches the papillae; papillae distinct, rounded to ovoid in plan 

 view, with a slightly raised profile, maximum diameter 4-9 |am. 

 Trilete-folds, or smooth lips, occur in some specimens and are 

 narrow over the apical area and expand towards the equator. 



Dimensions. 27-58 pm (59 specimens measured). 



Comparisons. Scylaspora elegans sp. nov. differs from proxi- 

 mally tripapillate A/;;W?/5/7onY« species by its proximal microrugulae 

 and apical darkened area (lips) bordering the trilete mark. The 

 photograph of the holotype of Ambitisporites? eslae Cramer & Diez 

 (1975: pi. 1, fig. 1 1) lacks this feature and has a wide crassitude. 

 Retusotriletes maculatus has proximal curvaturae invaginated at 

 their radial apices. 



Remarks. The current investigation revealed that Retusotriletes 

 eslae Cramer & Diez includes two distinct forms. The original 

 holotype has a broad equatorial crassitude, trilete folds and appears to 

 lack the apical, gradually tapering and darkened areas that flank the 

 trilete mark. Specimens with a broad crassitude are rare in the samples 

 studied (eg. PL 5, fig. 1 ) and it is not known whether such forms have 

 a proximal microverrucate sculpture. It has not been possible to study 

 the holotype for this purpose and. although Cramer & Diez described 

 microrugulae, their diagnosis states that the proximal surface is 

 'smooth to microrugulate" . Pending re-examination of the type material 

 the forms with a broad crassitude are retained but referred to as 

 Ambitisporites? eslae (Cramer & Diez). The more commonly occur- 

 ring spores, with a narrow, more or less equatorial, curvatural crassitude, 

 distinct trilete area and proximal microrugulae, are transferred to the 

 new species Scylaspora elegans. The microrugulae can be seen under 

 the light microscope in some specimens but under the SEM all spores 

 of this species show microrugulae that decrease in size towards the 

 proximal pole. Both species occur in all sections but data from the 

 present study shows that S. elegans sp. nov. occurs at the base of the EC 

 Biozone whereas /I ? eslae (Cramer & Diez) comb. nov. occurs first in 

 the Aneurospora Subzone at the top of the EC Biozone. In the 

 Cantabrian Mountains Scylaspora elegans sp. nov. occurs in strata 

 equivalent to the Upper/uppermost Pf idolf and extends into the Lower 

 Lochkovian (Devonian) and may, therefore, help in establishing the 

 Silurian/Devonian boundary. 



Occurrence. Upper San Pedro Formation, Argovejo. Geras, La 

 Peral and La Vid sections, EC Biozone to Lower MN Sub-Biozone, 

 Upper Ph'doli to Lower Lochkovian. 



Scylaspora cf. scripta Burgess & Richardson 1995 



PI. 5, fig. 9 



Dimensions. 23-29|im (3 specimens measured). 



Occurrence. La Vid, samples 6, 7B. 8A. 



Scylaspora vetusta (Rodriguez) comb. nov. 



PI. 3, fig. 5; PI. 5, figs 5-8; PI. 6, fig. 1 



BasioNYM. Archaeozonotriletes vefM5r«.v Rodriguez, 1978b: 219, 

 pi. l,fig. 8. 



1973 Emphanisporitesl sp. D, Richardson & loannides (pars): 



276, pi. 3, fig. 9 only. 

 1978b Archaeozonotriletes vetustiis Rodriguez: 219, pi. 1, fig. 8. 

 1978c Archaeozonotriletes chuliis Rodriguez: p\. l.fig. 14. 

 1978c Archaeozonotriletes vetustus Rodriguez: 414, pi. 2, figs 7. 



8. 

 1983 Archaeozonotriletes vetustus Rodriguez: 32, pi. 1, figs 2, 



18,20. 

 1995 Rugosisporites cf. chartulatus (McGregor); Dufka (pars): 



71,pl. 2, figs9-14. 



Holotype AND TYPE LOCALITY. Rodriguez, R.M. 1978b:pl. l,fig. 

 8: Corniero village. Province of Leon, Cantabrian Mountains, north- 

 west Spain, lower San Pedro Formation, ?Ludfordian. 



Emended diagnosis. A Scylaspora with closely spaced, more or 

 less radial, anastomosing, irregularly sinuous, muri/rugulae on the 

 proximal surface; distally laevigate apart from a narrow subequato- 

 rial area with +/- radial muri. 



Dimensions. 28-72 \im (60 specimens measured). 



Remarks. Spores of this species are highly variable. In some 

 cases there are irregular muri/rugulae that reach the pole, in others 

 cuneiform elements are prominent over the equatorial crassitude but 

 sculpture is faint to indistinguishable over the rest of the proximal 

 surface. Intermediates occur where distinct equatorial sculpture 

 becomes increasingly faint leaving a laevigate apical zone. The 

 equatorial crassitude is variable in width. 



PLATE 6 



Fig. 1 Scylaspora vetusta (Rodriguez) comb. nov. la, BM 140019, proximal view. LP92/10/DP; lb, BM 134179. proximal view showing subequatorial 



radial muri and scabrate apical area, sample Geras 92/7; Ic, BM 134195, proximal view, showing irregular proximal sculpture. Arg92/4A/1. 

 Fig. 2 Scylaspora sp. BM 135 15 1 . strong broad equatorial crassitude and coarse sinuous proximal muri. Ger2B/2. 

 Fig. 3 Coronaspora primordiale (Rodriguez) Rodriguez 1983. BM 137485, proximal view showing inter-radial thickenings, grooved crassitude and lips, 



Ger2B/2. 

 Fig. 4 Iberoespora cantabrica Cramer & Diez 1 975. 4a, BM 1 1 605 1 , proximal view showing chevron-shaped elements forming the labra, Arg92/7; 4b, 



BM 137480, proximal view showing inter-radial thickenings, Argl3/Dii. 

 Fig. 5 Iberoespora glabellal Cramer & Diez 1975. BM 129724, distal view showing concentric furrow inside equatorial crassitude and foveolate- 



muromate sculpture over central area, Arg92/1 IB. 

 Fig. 6 Coronaspora cromatica (Rodriguez) Jansonius & Hills 1979. 6a, BM 1345 10, proximal view showing variably developed verrucate lips, kyrtome 



and inter-radial muri, Ger92/2B; 6b, BM 134199, proximal view, showing kyrtome. inter-radial thickenings and verrucate labra, Arg5A/l; 6c, BM 



137269, distal view showing annulus and irregular muri in polar area, Ger92/2B/2; 6d, BM 135144, oblique compression showing equatorial crassitude 



and distal annulus, Ger92/2B/1 ; 6e, BM 134634, proximal view showing well-developed verrucate labra. Ger92/2B; 6f, BM 134634, detail of proximal 



apical area in Fig. 6e, x 2000. 

 Fig. 7 Coronaspora reticulata sp. nov. 7a, BM 138958, oblique proximal view showing kyrtome. LV92/7b/DDl ; 7b, BM 138395. proximal view showing 



kyrtome and thin apical area. 

 Fig. 8 Scylaspora elegans sp. nov. 8a, BM 2548, proximal view, Arg 92/1 1 B/2: 8b, BM255 1 , detail of proximal microrugulae, tilt 45°, x 4000. 



All figs X 1000, unless stated otherwise. 



