Paleontology terms with tricky plural or singular forms

[Halichoeres]

Even if you have taken a lot of classes in geology or biology, a lot of terms in paleontology or adjacent fields aren't included in a typical student's training. People can be forgiven for not knowing the etymology or standard plural or singular forms of words describing anatomy or concepts in evolution. So I've put together this little list for reference. This is just to be helpful; I'm not criticizing anyone's usage and generally speaking, if you're getting your point across, that's what really matters. And sometimes when terms like these get incorporated more fully into everyday English they gain new plurals that ignore the Greek and Latin roots (e.g., "femora" is the most etymologically correct plural for "femur," but "femurs" is roughly 20× as common in Google results).

biceps is both plural and singular; "bicep" is erroneous. Etymologically, I think the plural should be "bicipites," but nobody uses it and it's too late to start.

ceratotrichium (s.), ceratotrichia (pl.): the small flexible cartilaginous rods that, when joined together, support the fins of chondrichthyans and some early fishes such as arthrodires.

centrale (s.), centralia (pl.): a bone in the wrist or ankle (carpus or tarsus) of some animals. In humans there is one in the wrist of embryos but it usually fuses with the scaphoid. Some other bones with "-are" or "ale" singulars follow the same pattern (e.g. "fibularia")

centrum (s.), centra (pl.): the usually cylindrical main body of a vertebra.

fenestra (s.), fenestrae (pl.): larger openings in bones, especially the openings between struts of dermal bone in the face.

fibula (s.), fibulae (pl.): usually the smaller of two bones between the knee and the ankle. "Fibulas" is becoming more common.

foramen (s.), foramina (pl.): a passage through a bone, such as one that nerves or blood vessels pass through.

genus (s.), genera (pl.): the taxonomic rank above species. The plural is pronounced "JEN-ə-rə." Arguably the smallest unit that actually matters in vertebrate paleontology, but it depends on your working concept of species.

hemipenis (s.), hemipenes (pl.): The copulatory organ(s) of squamates. Most people only see the plural because this is always a paired structure. The singular has a pretty obvious pronunciation, but the plural is almost always mispronounced. It has four syllables: "HEM-i-pee-neez"

lepidotrichium (s.), lepidotrichia (pl.): the usually tiny dermal bones that are stacked end to end to make up the flexible rays of ray-finned fishes

manus is both singular and plural and refers to the metacarpals and forelimb phalanges collectively. I learned recently, to my horror, that it rhymes with "anus."

naris (s.), nares (pl.): in most usage, just a fancy word for nostril, but it can also refer to the choana, which is the internal nostril in sarcopterygians (actinopterygians and chondrichthyans usually have four external nostrils and they are used only for smelling, not breathing). The plural does not rhyme with "cares," it is two syllables and rhymes with "Ares."

pelvis (s.), pelves (pl.): the bones that anchor the pelvic fins of fishes, or their derivatives, the hindlimbs of tetrapods. Includes the pubis, ilium, and ischium in most tetrapods. Plural pronounced "PELL-veez"

pes (s.), pedes (pl.): the metatarsals and phalanges of the foot, collectively.

phalanx (s.), phalanges (pl.): any of the individual bones making up the toe or finger of a tetrapod. You have 14 phalanges in each hand: 3 in each finger and 2 in each thumb. A knuckle is a joint between one phalanx and the next.

pubis (s.), pubes (pl.): this is almost as unfortunate as the pronunciation of "manus." The plural is pronounced "PEW-beez."

sacrum (s.), sacra (pl.): collective term for the fused vertebrae that anchor the pelvis.

species is both singular and plural. Confusion is understandable, especially because in Spanish, for example, especie is a singular distinct from the plural especies

syrinx (s.), syringes (pl.): the vocal apparatus of a bird. We get "syringe" from an inflected form of the same Latin root.

taxon (s.), taxa (pl.): any entity of interest in a comparative or evolutionary analysis. In phylogenetics, it means every individual included in the analysis and hence every tip on the resulting cladogram. In other contexts, it means a named group: a species, a genus, a family, a superorder, whatever. Although a clade is by definition monophyletic, a taxon can be paraphyletic or polyphyletic. Good practice in modern taxonomy is to try to make taxa conform to clades.

testis (s.), testes (pl.): By now you are probably noticing a pattern where a term that ends in "-is" is pluralized with "-es." This should be familiar from words like parenthesis/parentheses or crisis/crises.

tibia (s.), tibiae (pl.): usually the larger of two bones connecting the knee and ankle. "Tibias" is becoming more common.

triceps is both plural and singular; "tricep" is erroneous.

vertebra (s.), vertebrae (pl.): I often see the plural used where the singular is more appropriate. You might be noticing another pattern where words ending in "-a" pluralize to "-ae."

I hope this is useful. Feel free to suggest others!

[Stegotyranno420]

Thanks for sharing. I always like it when two or more of my hobbies overlap, in this case, Biology and Language.
This also taught me a bit of Latin grammar rules.
As for some words, such as 'genus', are mispronounced(based on Classical Latin), though I am 100% aware these terms are utilized for science rather than Latin speech.
In classical Latin, it would be pronounced as something that could be approximated as [ɡɛnʊs̠] in IPA, but often is pronounced as [ˈd͡ʒɛːnus] in English.
Tangents aside, I applaud you for your presentation of biological diction.

[Faelrin]

I had already gone out of my way to educate myself on some of these terms especially after wanting to read paleontological papers, but I'm not familiar with all of these here so thanks for sharing and teaching them.

[ceratopsian]

There is no linguistic reason for "manus" to rhyme with "anus".  The "a" is short in Latin, not long.  Just like the way we pronounce "manumission" or "manufacture" in English, which have the same root.

[Concavenator]

Thank you for starting this thread @Halichoeres , I think it will come handy. Actually I would suggest it to be stickied, for future reference.

Even though not strictly related to the main point of the thread, just as a reminder, the proper way to indicate a species' whole name is: the genus has the first letter in cap and the specific epithet in lowercase letters. As for the abbreviations,it is correctly expressed with the first letter of the genus in cap, followed by a . and then the specific epithet in lowercase letters.  For example: Chlamydomonas reinhardtii. Abbreviated: C.reinhardtii.

I know this is very basic, but it genuinely annoys me to see people type Tyrannosaurus Rex, or T-Rex, T.Rex...

[Libraraptor]

I learned Latin at school and after three years I got my degree, the so called "Latinum". Thanks for sharing, I think this will be helpful.

[Halichoeres]

Thanks for the feedback, everyone, I'm glad it will find some use!

Thanks for sharing. I always like it when two or more of my hobbies overlap, in this case, Biology and Language.
This also taught me a bit of Latin grammar rules.
As for some words, such as 'genus', are mispronounced(based on Classical Latin), though I am 100% aware these terms are utilized for science rather than Latin speech.
In classical Latin, it would be pronounced as something that could be approximated as [ɡɛnʊs̠] in IPA, but often is pronounced as [ˈd͡ʒɛːnus] in English.
Tangents aside, I applaud you for your presentation of biological diction.

I'm also fond of language, although I only really speak two. I think it's only natural that we immigrants' kids would take an interest in it.

As for pronunciation, yeah, some of these would be wildly different if we were speaking Greek or Latin rather than technical English. Coelacanth would be something closer to "KOI-la-kant^h". I thought about giving pronunciations in IPA, but the trouble is that English speakers in different places have different vowel inventories. The "a" phoneme I use in "nares" is different from the one somebody in New York would use, let alone somebody in Britain or India or Australia.

There is no linguistic reason for "manus" to rhyme with "anus".  The "a" is short in Latin, not long.  Just like the way we pronounce "manumission" or "manufacture" in English, which have the same root.

You're right of course! I think that might be part of why I was so caught off guard when I found the long "a" in an anatomy text, and then again in every dictionary I consulted. Even other anatomical terms with the same root, like manubrium, use the short "a."

Thank you for starting this thread @Halichoeres , I think it will come handy. Actually I would suggest it to be stickied, for future reference.

Even though not strictly related to the main point of the thread, just as a reminder, the proper way to indicate a species' whole name is: the genus has the first letter in cap and the specific epithet in lowercase letters. As for the abbreviations,it is correctly expressed with the first letter of the genus in cap, followed by a . and then the specific epithet in lowercase letters.  For example: Chlamydomonas reinhardtii. Abbreviated: C. reinhardtii.

I know this is very basic, but it genuinely annoys me to see people type Tyrannosaurus Rex, or T-Rex, T.Rex...

Yeah, not the sort of thing I was thinking, but another convention that many probably aren't aware of. Even people who have taken biology often don't know this because it honestly isn't relevant or interesting to most people who take biology! To sum up:

[Strepsodus]

I've seen people equate genus to species and it drives me insane

[Stegotyranno420]

I've seen people equate genus to species and it drives me insane

Same. They usually say it in a sense where it's technically correct but you know they probably are equating genus to species.

[Halichoeres]

You mean by, for example, referring to Kentrosaurus as a "species" of dinosaur? That's the sort of thing I can't really get mad about. Species in extant organisms and species in the fossil record don't even mean comparable things, at least not when it comes to terrestrial vertebrates. It's almost never really important that the distinction be made except in technical literature, and even then species are extremely shaky entities. And just to reiterate, the spirit of this thread isn't to nitpick people's usage, it's to help people who want help and that's it.

List edited to include 'triceps' and 'biceps.' I left out 'quadriceps' but it follows similar logic.

[Newt]

Excellent idea for a thread! I have seen quite a few mistakes in pluralization even in peer-reviewed papers; I suppose fewer and fewer reviewers (say that three times fast!) nowadays have the education or interest to catch them.


One that always gets me is centrale (s.), centralia (pl.) - bones of the carpus and tarsus of certain basal tetrapods. I suppose ulnare, radiale, tibiale, fibulare follow the same pattern, but I don't see those pluralized as there is only one per limb, whereas there may be a few centralia.

If we follow classical pronunciation, then Centrosaurus and Kentrosaurus would be pronounced exactly the same! In (possible) fact, I hazily recall that some scientists considered the name Kentrosaurus to be preoccupied by Centrosaurus (or the other way around, I don't remember which name is older) and insisted the animal needed a new name. Obviously they did not prevail, assuming this happened at all and I didn't just make it up in some sort of pedantic hallucination.

[Stegotyranno420]

Yep, and Ceratosaurus will be Keratosaurus.
Neovenator will be NEH-O-WEH-NA-TOR(tho I cannot write the  pronouciation  properly without IPA)

[Halichoeres]

Centralia is an interesting one! I'd never considered it because I never had occasion to refer to more than one. I'll add it to the list.

On the subject of Ks and Cs, one of my grad committee members was from northeast England and pronounced things like "cephalopod" or "holocephalan" with a hard K sound ('holo-KEFF-ə-lən'). But once I asked him the name of Alexander the Great's horse, and he said, a little abashedly, "byu-SEFF-ə-ləs." Almost nobody applies the pronunciation conventions universally, which inclines me to be pretty relaxed about them.

[Duna]

On the subject of Ks and Cs, one of my grad committee members was from northeast England and pronounced things like "cephalopod" or "holocephalan" with a hard K sound ('holo-KEFF-ə-lən').

That's "incorrect". That would be correct in the "classic or cult" latin way, that is not used in scientific nomenclature talking but the vulgar latin.
So in the middle of words "C" is not "K" sound but "C" (SE). Neither in Spanish. In this video it's explained perfectly how it's pronounced in Spanish (using the correct way that is vulgar latin).
However, some other Spanish speaker paleontologists or video makers pronounce other words incorrectly influenced by English pronunciation. For example, latin ending diptongoes - ae and -oe are pronounced -/e/ in vulgar latin. Not -ei or -ai or whatever.
So "hominidae" is pronounced "Hominid/e/" ... "Bovid/e/" ..., "Canid/e/". Most letters are pronunced the way they are written, as all words in Spanish, but some are pronounced the vulgar latin way. Perfectly explained in this video:

https://youtu.be/6SrZCiFK-ks
If you open the video in Youtube page, then select Subtitles, then in Subtitles submenu you can chose Traslate automatically to English or other languages.

[Crackington]

I'm from North East England originally and I would pronounce "cephalapod" with the softer sound. I don't think it's a particularly regional thing, though it's not exactly a commonly used word in the Geordie or Makem dialect, do ya knaa worra mean marra? 

[ceratopsian]

I agree. I don't think the hard C was regional.

Other factors can play into pronunciation choices for words of foreign origin. For instance when I was in my late 20s I started going to a local branch of the British Cactus and Succulent Society. The closet person to me in age and also new to the hobby was a woman who was in her last school year pre university. She was studying Latin. I had degrees in the Classics. We got on like the proverbial house on fire, not least because we were female in a rather male hobby in those days. We both quickly grasped our plant scientific names as Latin and Greek gave us no difficulty and usually conveyed some meaning to us. But we hadn't heard the other members say them, only seen them written down in books. So it was a rude awakening when we realised that the hard Cs and Gs etc, second nature to us, caused complete confusion with everyone else. We quickly adjusted to the norm - but when chatting together tended to revert to our old "private language" version.

Another quirk for me: if I see an obviously foreign word in a language I don't know at all, I tend to pronounce it as if it came from a foreign language where I am familiar with the sound - usually Italian. Which of course usually ensures a completely incorrect sound!

I'm from North East England originally and I would pronounce "cephalapod" with the softer sound. I don't think it's a particularly regional thing, though it's not exactly a commonly used word in the Geordie or Makem dialect, do ya knaa worra mean marra? 

[Halichoeres]

That's good to know. It didn't seem like the sort of thing that would be regional, but I'm never sure with Britain because, compared to the States, the variety of dialects is pretty bewildering. Seems to be a somewhat pedantic idiosyncrasy then.

Another quirk for me: if I see an obviously foreign word in a language I don't know at all, I tend to pronounce it as if it came from a foreign language where I am familiar with the sound - usually Italian. Which of course usually ensures a completely incorrect sound!

I tend to default to Spanish pronunciation rules unless I know otherwise, and that leads me astray too sometimes, especially with stress patterns. I am especially bad at predicting stress in words from Bantu languages.