Since its foundation, the Commission has considered numerous applications dealing with the names of fossils including foraminifera, brachiopods, molluscs (e.g. ammonites), arthropods (e.g. trilobites), graptolites, reptiles (e.g. dinosaurs), birds (e.g. Archaeopteryx) and mammals.
Fossil foraminifera are crucial indicators in biostratigraphy, palaeoecology, palaeobiogeography, and oil exploration. Fossils of these single-celled organisms (protists) are widely used for dating purposes and as zonal markers, indicating the potential oil-bearing nature of the sediments in borehole cores. Such is the stratigraphic precision of these fossils that they are even used to direct sideways drilling within an oil-bearing horizon to increase well productivity. The Commission has ruled on such key genera as Alveolina, Anomalina, Borelis, Discocyclina, Endothyra, Globigerina, Nummulites, Orbulina, Pseudoschwagerina and Sorites, in many cases defining these genera by determining their type species. [1945-1998]
Ammonites are important indices for stratigraphical investigations. A recent application proposes the stabilisation of the usage of names of Jurassic ammonites and that 34 names of important species or subspecies, being either type species of genera or indices of standard chronostratigraphic Zones and Subzones, be placed on the Official List of Specific Names in Zoology. Important zonal or subzonal index fossils included in this case are:Ammonites biplex bifurcatus, index of Bifurcatus Zone, Middle Oxfordian, and Ammonites polymorphus, index of Polymorphites polymorphus Subzone, Jamesoni Zone, Pliensbachian. 
Trilobites are the single most diverse group of extinct organisms. These Palaeozoic marine arthropods exhibited an immense diversity of size and form and thus are of great stratigraphic and palaeoecological importance. An application for the conservation of the name Cryphops, for a genus of Late Devonian trilobites, was a benchmark case for the Commission: it was the first case to be placed, in its entirety, on the World Wide Web, stimulating comments from the academic community concerned with the taxonomy and stratigraphic importance of these organisms. 
Iguanodon Mantell, 1825, a gigantic herbivorous terrestrial reptile of Cretaceous age, was one of three early fossil discoveries made in England that led to the term Dinosaur (from the Greek ‘deinos’ meaning fearfully great, and ‘sauros’ meaning lizard) being coined by Owen in 1842. Fossils of Iguanodon (meaning ‘iguana tooth’) have been found in Europe (England, Belgium and Germany), northern Africa and North America. The Commission defined the genus Iguanodon by designating its type species, Iguanodon bernissartensis. 
Ichthyosaurus species (meaning ‘fish lizard’), ichthyosaurs, were marine reptiles, contemporary with dinosaurs, living from the Middle Triassic until the early Cretaceous age. Ichthyosaurus species were about 2 metres long and may have weighed up to 90 kg. They had a tall dorsal fin, a half-moon-shaped tail, paddle-like flippers, and smooth skin. Ichthyosaurus fossils have been found in England, Germany, Greenland, and Canada. The Commission has defined the ichthyosaur speciesIchthyosaurus trigonus Owen, 1840, and Ichthyosaurus cornalianusBassani, 1886 by determining their type specimens. [1993 & 2001]
Tyrannosaurus vs. Manospondylus and Apatosaurus vs. Brontosaurus: not battles of the dinosaurs but arguments about dinosaur names. A recent amendment in the Commission’s International Code of Zoological Nomenclature (1999), allows names fixed in popular usage to be validated even if older designations have technical priority. The name Tyrannosaurus rex (meaning ‘tyrant lizard king’) Osborn 1905 has been used for about a hundred years, nearly as long as its synonym Manospondylus gigas had been forgotten. In this case by judicious application of The Code the reign of T. rexcan continue. However, in contrast, the name of the giant herbivore,Brontosaurus (‘thunder lizard’) Marsh, 1879, has been sunk, with the older name Apatosaurus (‘deceptive lizard’) Marsh, 1877, replacing it. Both names were widely used for a long time but the consensus among palaeontologists here was that a name change would not be too upsetting. Stephen Jay Gould wrote that Brontosaurus was ‘everyone’s typical sauropod, indeed the canonical herbivorous dinosaur of popular consciousness from the Sinclair logo to Walt Disney’s Fantasia’, yet this name has been abandoned.