. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. , QUATERNARY OSTRACODS FROM SOUTH-WESTERN AFRICA 397. Depth (km) Palmoconcha walvisbaiensis Cytherella namibensis Bensonia k. knysnaensis Pseudokeijella lepralioides Ruggieria cytheropteroides Henryhowella melobesioides Fig. 8. Variation of species dominance with depth across the continental margin. Constructed by projecting all data points on to a single axis, and smoothing each curve with a five-point running mean. lepralioides on the mid-outer shelf. Immediately south of Walvis Bay, there is a
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. , QUATERNARY OSTRACODS FROM SOUTH-WESTERN AFRICA 397. Depth (km) Palmoconcha walvisbaiensis Cytherella namibensis Bensonia k. knysnaensis Pseudokeijella lepralioides Ruggieria cytheropteroides Henryhowella melobesioides Fig. 8. Variation of species dominance with depth across the continental margin. Constructed by projecting all data points on to a single axis, and smoothing each curve with a five-point running mean. lepralioides on the mid-outer shelf. Immediately south of Walvis Bay, there is a mixed assemblage containing Palmoconcha walvisbaiensis and Bensonia k. knysnaensis. A further mixed zone occurs between c. ° and 34°S, where the two dominant taxa are 'diluted' by the relatively diverse and abundant faunas off the south-western Cape (which contain many of the rarer taxa described by Dingle 1993). Outer-shelf and uppermost-slope areas are dominated by two species: Cytherella namibensis in the north and Ruggieria cytheropteroides in the south. Upper and mid-slope areas are dominated by Henryhowella melobesioides, with a narrow mixed zone contain- ing abundant Krithe (mainly K. capensis) and the deeper-water species of Buntonia (B. rosenfeldi, B. bremneri and B. namaquaensis) intervening between the Cytherella namibensis-Ruggieria cytheropteroides upper-slope assemblage and the Henryhowella melobesioides upper-mid-slope assemblage. All three inner-outer-shelf dominant species typically constitute 40 50 per cent of the local populations; projecting their abundances on to a cross-shelf axis (Fig. 8) empha- sizes that each taxon reaches its individual maximum at diflferent depths: Bensonia k. knysnaensis, 50 m; Palmoconcha walvisbaiensis, 80-110 m; and Pseudokeijella Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not
Size: 2317px × 1079px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
