dorsal suture การใช้

The primitive state of the dorsal sutures is proparian.
The thorax has the continuous dorsal suture across the middle, along with well-defined posterior calli.
The Fallotaspidoidea remain paraphyletic ( hence the quotation marks ), even after reorganizing it, because it gave rise to the trilobites with dorsal sutures.
The pods are small, sessile, puberulent to strigose, spreading to declined, often humistrate, in profile ovoid-oblong, straight or a trifle incurved, obtuse at base, abruptly acute at apex to short-mucronate, thickened, incompletely to fully bilocular ( 2-celled ), cordate in cross-section, trigonous or compressed-triquetrous, the lateral faces flat, the dorsal ( upper or adaxial ) face narrower and sulcate ( grooved ), carinate by the ventral suture, the dorsal suture shallowly to deeply sulcate; thin, papery, green to stramineous ( brownish ) valves strigulose, 4 7 mm long, 1?2?mm in diameter, deciduous from receptacle, dehiscence primarily basal and occurs after falling.