Paradoxides sentence example
- In Paradoxides, for example, there are about twenty freely movable segments followed by a very short and small pygidium, whereas in Agnostus the freely movable segments are reduced to two and the pygidium is as large as the cephalic shield.
- The posterolateral angles of the gena are commonly produced into spiniform processes, which may project backwards beyond the middle of the body as in Paradoxides, or considerably beyond its posterior termination as in Trinucleus or Ampyx.
- Those genera, like Paradoxides, Olenus, Asaphus, Phillipsia and others, in which this groove cuts the posterior edge of the head-shield on the inner side of its angle are referred to the Opisthoparia; those, like Dalmanites and Phacops, in which it cuts the lateral border in front of the posterior angle, belong to the Proparia.
- The middle part of the system, characterized by the Paradoxides fauna, is somewhat more widespread, resting on the lower part conformably, but overlapping it, especially in the south and west.
- In the Cambrian period trilobites had already attained their maximum size; some species of Paradoxides were nearly 2 ft.Advertisement
- Thus we have a Lower Cambrian with Olenellus, a middle series with Paradoxides and an Upper Cambrian with Olenus.
- On the North American continent, as in Europe, the Cambrian system is divisible into three series: (i) the lower or "Georgian," with Olenellus fauna; (2) the middle or "Acadian," with Paradoxides or Dikelocephalus fauna; (3) the upper or "Potsdam," with Olenus fauna (with Saratogan or St Croix as synonyms for Potsdam).
- In the middle series (Paradoxides) three thin limestone bands have been distinguished, the Fragmenten-Kalk, the ExulansKalk and the Andrarums-Kalk.
- Above the fucoidal sandstone an important break appears in the system, for the Paradoxides and Olenus divisions are absent.
- In Russian Poland is a series of conglomerates, quartzites and shales; some of the beds yield a Paradoxides fauna.Advertisement
- The upper divisions consist of bituminous limestones, clay-slates, alum-slate, and contain numerous species of trilobites of the genera Paradoxides, Conocoryphe, Agnostus, Sphaerophthalmus, Peltura, &c. The Ordovician formation occurs in two distinct facies - the one shaley and containing graptolites; the other calcareous, with brachiopods, trilobites, &c. The most constant of the calcareous divisions is the Orthoceras limestone, a red or grey limestone with Megalaspis and Orthoceras.
- Genera with small metasomatic carapace, consisting of three to six fused segments distinctly marked though not separated by soft membrane, are Harpes, Paradoxides and Triarthrus (fig.