Nd peristomium to segments five. Its integument is thin, delicate, and also the
Nd peristomium to segments five. Its integument is thin, delicate, and also the initial three chaetigers carry falcate hooks. The constricted area typically incorporates only segments 7, carries the genital papillae, and is followed by an expanded abdomen, which is the largest part of the physique. The anterior abdomen has some segments with no chaetae in the adult stage, whereas the posterior abdomen carries PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/11836068 the ventrocaudal shield, its related marginal chaetae, and two dorsal groups of branchial filaments, commonly arranged in discrete branchial plates. You will find 3 body patterns among the Sternaspis species regarding their shield type, introvert hooks, and the number of abdominal segments. The first pattern incorporates most species. They’ve shields using a continuous, stiff layer usually carrying radial ribs, concentric lines, or each, and their sediment cover is simply brushed off; their introvert hooks are cylindrical, tapered, and their anterior or JW74 biological activity preshield abdomen has seven segments. This pattern is regarded as Sternaspis sensu stricto. The second pattern incorporates two species, one being newly described under, and their shields are remarkably soft, without having ribs or concentric lines, but their sediment cover is firmly adhered such that it can not be brushed off; their introvert hooks are cylindrical, tapered, and their anterior or preshield abdomen has seven segments. For this pattern, Caulleryaspis gen. n. is becoming proposed. The third pattern also consists of two species with one particular newly described under. Their shields are stiff, with ribs but without having concentric lines, and their sediment cover is conveniently brushed off; their introvert hooks are subdistally expanded, or spatulate, and their anterior or preshield abdomen has eight segments. Petersenaspis gen. n. is getting proposed to consist of these two species. The relevant morphological functions in sternaspids are shown in Table 
.Kelly Sendall Sergio I. SalazarVallejo ZooKeys 286: four (203)table . Main morphological options of Sternaspis Otto, 82, Caulleryaspis gen. n. and Petersenaspis gen. n. species [shield characteristics are surface (S), anterior margins (A), anterior depression (D), lateral margins (L), and fan (F)]. Species S. affinis Body papillae Rows of clusters Shield Lateral shield chaetae 0 in oval pattern 9 in oval pattern 9 in oval pattern Posterior shield chaetae five in linear pattern five in slightly curved pattern 5 in linear pattern Peg chaetae Present Present Present PresentS ribs and conc. lines. A rounded. D deep. L rounded. F crenulated. S ribs. A angular. D deep. S. africana Rows of L rounded. F denticulated, stat. n. clusters crenulated in bigger specimens. S barely ribs. A angular. S. andamanensis Absent D deep. L rounded. F sp. n. denticulated, notched laterally. S ribs and conc. lines. A Two rows of rounded. D shallow. L S. costata clusters rounded. F deeply notched. Abundant, evenly S ribs, tenuous conc. lines. A S. fossor distributed, rounded. D deep. L rounded. F notched, smooth. rows of clusters S ribs and conc. lines. A Rows of S. islandica rounded. D deep. L rounded. F clusters truncate, notched, smooth. Abundant, S ribs, no conc. lines. A S. maior evenly rounded. D shallow. L distributed rounded. F crenulated. S ribs, no conc. lines. A Evenly S. princeps rounded. D deep. L rounded. F distributed truncate, crenulated. Probably S covered. A rounded. D S. rietschi evenly shallow. L rounded, crenulated. distributed F truncate, crenulated. S ribs and conc. lines. A Evenly S. scutata truncate.
