Nina Tchernysheva

Professor N.K. Ivshin was an expert on trilobites and Cambrian stratigraphy of Kazakhstan. Before he began his work, Cambrian trilobites were almost unknown in Kazakhstan. Only a small monograph by E.V. Lermontova on Late Cambrian trilobites of Boshchekul had been published in 1951. Ivshin was the first paleontologist to study Middle Cambrian trilobites. He was very fond of field work and his collections are huge. When he began his scientific work in the 1950s there were no reference publications on trilobites in Alma-Ata. He managed to get microfilms of books and papers from Leningrad and assembled a fairly complete library of photocopies.

An extremely hard worker, Invshin published four important monographs -- two on the Middle Cambrian (1953 and 1957) and two on the Upper Cambrian (1956 and 1962) plus several papers in a ten year period. Apart from detailed descriptions of species, these monographs provide substantial critical reviews of the genera. In his lifetime, he established about 60 genera of trilobites and more than 150 species.

A thorough analysis of entire trilobite faunas allowed Ivshin to establish a succession of faunal assemblages through time, to correlate sections, and to compile a unified biostratigraphic chart for the Middle and Upper Cambrian of north-eastern Central Kazakhstan. Many of these trilobites have a wide geographic distribution. Ivshin also studied the stratigraphy of the Altai-Sayany fold area and the Siberian Platform and proposed a stage subedivision for the Upper Cambrian. During the last years of his life, Nikolai Ivshin was critically ill and his paleontological studied were limited. He published a monograph on Early Cambrian trilobites of Kazakhstan (1978), but focussed his attention on improvements to the stratigraphic chart for the Cambrian and on problems of correlation.

Gapper Ergaliev, Nikolai Ivshin and Nina Tchernysheva in the field in 1966. Agyrek, Kazakhstan.

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The First Trilobite Eggs?

Xiguang Zhang and Brian Pratt
University of Saskatchewan

In an upcoming issue of Science we report the discovery of phosphatized arthropod eggs from the lower Middle Cambrian of China. These eggs are gently ovoid, about 0.3 mm in size, and the embryo is preserved as tightly packed cells seen as polygons on the outer surface. We argue that they probably belong to the eodiscid trilobite that also occurs in the collections.