One of the many things I do in my so-called ‘spare time’ is proof-reading for friends that are students. This week I have been proof-reading an assignment for a friend on the taxonomy of arthropods. Throughout the assignment, many references were made to various orders, families and genera of Arthropoda. I’ve covered in detail before the rules and conventions regarding capitalisation and italicisation. I’d highly recommend reading that blog post to get your head around the basics of wrestling with scientific nomenclature before coming back and picking up here.
Scientific names and the way we write them are broken down into generic (genus), specific (species) and subspecific (subspecies) names. These three words are usually (but not always) Latin, and are referred to as the organism’s ‘scientific name’. The genus is always capitalised; the species is never capitalised; both are always italicised; the subspecies is always italicised and never capitalised. Occasionally, the authority – original describer – of the species and a year will be written in brackets after the species or (if there is one), the subspecies – and this is NOT italicised, but always capitalised [e.g. the tormentil mining bee: Andrena tarsata (Nylander, 1848)*scroll down to the bottom for a bit more on this!]. Sometimes you’ll see a subgenus thrown in too, between genus and species, both capitalised and italicised. [e.g. Bombus (Psithryus) rupestris]. Another thing you’ll see is ‘sp. or spp.’, which refers to an undetermined species (the former) or undetermined group of species (the latter). [See my other blog post for examples of this.]
I’ve always been pretty clear on this stuff, but one thing ‘they’ never teach you, is the accepted conventions for writing and talking about the higher classifications.
There are two hard-and-fast rules to help you remember:
- Everything genus and above is capitalised. This means that we always capitalise kingdom, phylum, subphylum, class, subclass, superorder, order, suborder, superfamily, family, subfamily and tribe.
- Everything genus and below is italicised. This means that we always italicise genus, subgenus, species and subspecies.
But, of course, there are some complications… A Eurasian badger [Note: there are rules for common names, too: I have capitalised Eurasian because it is a continent and therefore a proper noun – all common names that are proper nouns are capitalised; all others are not – so we capitalise ‘Leisler’s bat’ but not ‘water vole’; but I digress...] is in the family Mustelidae (capitals, no italics). We refer to members of the family Mustelidae as ‘mustelids’. This is not capitalised because it is basically an adjective. Let’s look at dinosaurs:
Tyrannosaurus rex is in the family Tyrannosauridae (capitalised). Albertosaurus sarcophagus is also in the family Tyrannosauridae. We would refer to both of these dinosaurs as being ‘tyrannosaurids’ [meaning: belonging to the Tyrannosauridae] or, more colloquially, as tyrannosaurs. Neither of these descriptors would be capitalised. You may also hear ‘tyrannosauroid’ [meaning: shaped like a member of the Tyrannosauridae] which would also, as an adjective, not be capitalised.
Another example is one of the groups that I study: aculeate Hymenoptera (bees, wasps and ants). Hymenoptera is the proper classification, so it is capitalised. Aculeata is a subclade of Hymenoptera, so if I were to write about studying Hymenoptera Aculeata, both would be capitalised. However, I tend to say that I study aculeate Hymenoptera. In this case, ‘aculeate’ is an adjective used to describe what kind of Hymenoptera I study, so it does not get capitalised. Furthermore, if I tell you that I study aculeate hymenopteran invertebrates, I don’t hit the shift key even once…
So there you go – clear as mud, right? Just remember that if it’s an adjective, it doesn’t get a capital letter, and follow the two rules above and you shouldn’t go wrong!
*So, to confuse things even further, the conventions in botany differ from the conventions in zoology. Basically, the authority goes in brackets if the species has been reclassified since its original description. In botany, this is followed by the reclassifier, not in brackets. In zoology, the reclassifier doesn’t get mentioned, but the date of the original description is inserted within the brackets.