Style of dinosaur names

I’m working on a short story narrated by a paleontologist. I know that when giving the genus and species name, the genus is supposed to be capitalized and both words are supposed to be italicized, like Triceratops horridus. When only the genus is specified, it is capitalized and italicized.

However, my story is a time travel story. There is no English name for most dinosaurs. So how would my hero refer to an animal he sees? He sees a triceratops? A Triceratops? A Triceratops? Webster’s Third International says the genus name is capitalized but the actual animal or its fossil is not. Does that sound right?

And what if there is more than one? Webster’s Third International says the plural is “triceratopses” but other sources say the “es” is optional. What about a herd? Is it a herd of triceratops or triceratopses?

Keep in mind that my narrator is not a layman.

Any help will be greatly appreciated.

The formal scientific name is constructed in Latin as a binomal phrase, normally with a coined noun, capitalized, for the genus and an adjective or possessive, without a capital, for the trivial (Species) name. Leporisaurus hispanicus (made up as an example for this post) would be “Spanish hare-lizard”.

Very few dinosaurs have English names distinct from their scientific names. Except T. rex , which normally akways takes the full binomial for a common name, virtually all dinosaurs are referred to by their genus name. English normally does not mandate the capital expected in the formal scientific name, and popular use normally takes regular English plurals. A professsional, though, would probably use an undeclined plural: “a herd of triceratopses” from a fifth grader or a reporter working science beat, but “a herd of triceratops” from the paleontologist writing for the public.

One thing that you might take into account is that the final -us is often dropped in producing English terms, particularly those dealing with closely related genera. “Megalosaurs were the common large carnivores of the Later Jurassic” would be a likely phrase, meaning Megalosaurus and possibly related genera. Another common Englishing is to drop the -ae from the family name, producing an English noun ending in -id(s), e.g. Brachiosaurids or Ornithomimids; another is to coin an English word using -ian(s), as in Ceratopsians.

I’m not the OP, but I am fascinated by dinosaurs and extinct creatures of all kind, so thanks, Polycarp! Very informative.

The question I did not address is that, although the scientific name is normally written in italics, its use as an English name is not. For example, “Diplodocus longissimus, commonly called the diplodocus…”

Thank you, Polycarp, that’s what I needed to know.