You can see two of them here. The lovely larger ammonoid with the oil-in-water colouring is Craspedites okensis (d'Orbigny, 1945). Craspedites is an ammonoid cephalopod included in the Perisphinctaceae that lived during the Late Jurassic and Early Cretaceous, found in Canada, Greenland, Poland and Russia.
The genus Craspedites was first described by Aleksei Petrovich Pavlow in 1892. It is characterized by a small — up to about 5 cm in diameter — smooth, involute shell with simple ammonitic sutures. The whorl section is rounded with a smooth centre and small umbilicus exposing the dorsal portion of the inner whorls. Craspedites was thought to be restricted to the Upper Jurassic Tithonian until the discovery of a new species, C. sachsi, from the Berriasian of Russia (A. E. Igolnikov, 2012) named in honour of palaeontologist V.N. Sachs.
The smaller ammonite you see on the bottom of this block is Craspedites sp. from Jurassic deposits of the Volgian Stage, the zone subditus — 150 - 140.2 million years old. The photo credit belongs to the deeply awesome Emil Black. This block is in his personal collection. If you're interested in learning more about the ammonites from Russia, there is a publication from Ernst Gerold Westermann you may want to read, The Jurassic Ammonite Zones of the Soviet Union, Issue 223.
A. E. Igolnikov (2012). Craspedites (Vitaliites?) sachsi, a New Boreal Berriasian ammonite species of the North of Eastern Siberia (Nordvik Peninsula) Paleontological Journal. 46 (1): 12–15. Here's the link if you'd like to read it:
