Correlation of Lower Cambrian rocks is hampered because there are no widespread and rapidly evolving organisms such as the later agnostids, graptolites, conodonts, ammonites, or planktonic foramini fers, that might provide basis for a consistent intercontinental biostratigraphy. Four problems illustrate issue: 1) age oldest trilobites China; 2) acritarch correlations between Siberia Baltica; 3)...

Conodont elements are the earliest vertebrate dental structures. The dental tools on elements responsible for food fracture-cusps and denticles-are usually composed of lamellar crown tissue (a putative enamel homologue) and the enigmatic tissue known as 'white matter'. White matter is unique to conodonts and has been hypothesized to be a functional adaptation for the use of elements as teeth. W...

Conodonts from the Ladinian-Carnian boundary interval in British Columbia are described. The study interval embraces the upper Ladinian/lower Carnian Maclearni, Sutherlandi, Desatoyense, Obesum, and Nanseni ammonoid zones. The following new species are described: Metapolygnathus acuminatus, Metapolygnathus intermedius, Metapolygnathus lobatus, Metapolygnathus zonneveldi, Neogondolella liardensi...

. Kojima, S., 1989, Mesozoic terrane accretion in Northeast China, SikhkoteAlin and Japan regions: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 69, p. 213-232. Kojima, S. and Mizutani, S., 1987. Triassic and Jurassic Radiolaria from the Nadanhada Range, Northeast China: Transactions and Proceedings Palaeontological Society of Japan, 148, p. 256-275. Kozur, H., 1984a, New radiolarian ta...