Three things to note here:
1. Ceratops montanus is not complete, and is based on incomplete cranial remains that are considered unusable for further taxonomic purposes. It is, in short, a nomen dubium.
2. The word ceratops is a Latinized compound of a set of two Greek words. This is more complicated than it sounds. It impacts everything from how the word is pronounced to how it is combined with other words, to how it is expressed in translation, etc.
3. Not all “ceratops” taxa are dinosaurs. There is a marked trend in taxonomy for some groups to use a prefix, infix, or suffix of a certain form for many taxa, and in dinosaurs this is no different: you get -titan for some sauropods, -pelta for some ankylosaurs, -raptor for small, predatory theropods, and of course, -ceratops for ceratopsians.
Ceratops montanus, the First Ceratopsian
Ceratops montanus, a dinosaurian taxon named for a partial skull , has become the basis of substantive popular taxonomy, rendering it a historically interesting subject. But for reasons of preservation and quality, the material on which the name is based (a pair of unconnected supraorbital horn cores, and an occipital condyle) is deemed insufficient for nomenclatural purposes by most workers [2-5]; it apparently lacks any apomorphies that distinguish it from any two taxa regarded as being similar to it (such as Avaceratops lammersorum, which it was at one time suggested as being synonymous with ). Material has been recovered which was at first considered Ceratops montanus , but this hasn’t been substantively treated in the literature, and it is unlikely that, based on the material seen below, the name can survive.
As you can see, there isn’t much there. For the last century or so, virtually all ceratopsid dinosaurs with long supraorbital horns were considered chasmosaurines, a group including the long-frilled ceratopsids, and a few oddities, including Triceratops horridus. Ceratops montanus is incredibly incomplete for a ceratopsian with cranial material, and the basic trends in description have gravitated towards describing taxa based on their frills, with some effort to describe features of the facial skeleton, and virtually no description of their postcrania. In this case, Ceratops montanus is simply out of luck. I am almost tempted that, because it is not possible to fully determine any diagnostic characters, character suites, nor can it be readily differentiated from several taxa, Ceratops montanus is a bona fide nomen dubium. But such a statement is old hat (just see the references at the bottom of this post).
Κερατωψ = κερατος + ωψ [n1]
This is an important string, as in the Greek it is pronounced KEH-rah-tohps, with a nearly long final “o” and a hard “k”. Latinization, producing ceratos (and hence cerato-[from ceratus]) and ops becomes -ceratops, and was pronounced somewhat differently especially when derived through later Latin: SAYR-ah-tahps, although it was more closer to SHAYR-ah-tahps.
When authors name taxa, they often provide etymologies with minor to major amounts of information; some relate their nomenclature from Ceratops directly, in the Latin form, or from -ceratops, as a derivative of the convention in which many similar or related taxa are named. Others, however, more strictly use the Greek string, separating the two original words. A third group will use the Greek lettering, but provide the combined string κερατωψ, from which one might assume the author is intending the original Greek lettering, but for the Latin structure implied when using -ceratops. No ceratopsian taxon has been named with -keratops, as would be expected from a more “originalist” (by which I mean “in the sense of the Greeks at the time the word was being used, and not how it was used by others much, much later than they”) Greek origin, despite the etymologies, and this is odd.
My impression of this, when it comes to pronunciation, is that people will pronounce it SAYR-ah-tahps regardless of its origin, although it seems that when the nomenclator (“person who names”) creates a word from Greek, it should be pronounced closer to the Greek string than the Latin; conversely, when one uses the Latin string, one would pronounce it as in Latin, rather than in Greek.
A second thing to note here is that the Latin (as well as the Greek original) form of ωψ, ops, is a root that combines from -op-, not -ops-. In this way, the name Ceratopsidae is incorrectly formed from the very beginning. While the trend of retaining the “s” in combining forms is excessive in ceratopsian systematics, it is entrenched, prompting every further author with an option not to do this, or do this and go “mainstream.” Some other authors have attempted to revise this by adopting the “correct” derivations and applying them to the name (forming Ceratopidae, Protoceratopidae, etc.) these names are incorrect emendations, due to the ICZN mandating original form in its construction of “family” group names, even if it’s wrong. This spelling error is certainly unique to dinosaurs; other types of -ops based taxa (e.g., in insects and trilobites, to name two broad groups) leave the “s” out.
I urge then that when forming a new construction one may use two principles: 1, the author can utilize the form that all other suprageneric taxa within Ceratopsia use, and leave the “s” in; or 2, the author can form a correct construction and leave the “s” out.
Finally, I want to note that when it comes to originalism in spelling and grammar for taxon names, I am amenable to convention, when present; I don’t actually think or act or talk as if every word is to be so prim and precise: but when I hear it claimed that there is a need to be precise and proper in pronouncing certain words (i.e., in agreement with Latin pronounciation) it seems [again] odd that this process is not expanded. Some linguists offer both preferred pronunciations, quite often for words likely to be unfamiliar even to those familiar with Latin and Greek, such as in names derived from First Nations tongues.
It would be nice to see more original spelling structure when people root their names based on specific languages and words, rather than presuming to convert them to Latin in some fashion. While taxonomy used to presume Latin as the codified arbiter of taxonomy composition, this is no longer the case, and pop culture, puns, personal names in their original form, and other languages have made it to taxonomy, and have persisted from the very beginning with Linnaeus himself (in the sense of puns, and such).
Ceratops in Taxonomy
To date, as of me writing this, there are now nearly 40 ceratopsian dinosaurs named with -ceratops. But there are other -ceratops taxa which are not dinosaurian, nor were ever intended to be dinosaurian. The most famous of these is Tetraceratops, but the following is a list of all (non-dinosaurian) taxa which end or contain -ceratops (as derived from the above root, and excluding names like Ceratopus (“horned foot,” a coleopteran):
Asiaceratops Nessov & Kaznyshkina vide Nessov, Kaznyshkina & Cherepanov, 1989 (a nonceratopsian ornithischian) [n2]
Biceratops Park & Gayle, 1971 (a trilobite)
Bolboceratops Krikken, 1978 (a coleopteran)
Camptoceratops Wenz, 1923 (a mollusk)
Ceratops Rafinesque, 1819 [n3]
Ceratopsion Strand, 1928 (a sponge)
Diceratops Förster, 1868 (a hymenopteran)
Megaceratops Cope, 1873 (a brontothere)
Microceratops Seyrig, 1952 (a hymenopteran)
Notoceratops Tapia, 1918 (non-ceratopsian ornithischian)
Tetraceratops Matthew, 1908 (a basal synapsid)
Of Ceratopsia itself, the string “ceratops” appears in 39 “generic” names, regardless of their current regard to validity (some of them are synonyms of other taxa) out of 62, which only stresses the use of -ceratops in ceratopsian nomenclature. While some of the first ceratopsian taxa named did not bear -ceratops, a large majority of them did early on. What follows is a short list of all ceratopsian taxa with -ceratops in their names. They are slightly annotated, so a short note on this: [npo] is used to denote a preoccupied name, and it will be followed by the name (and author) which came first; [nrn] marks a name which has been erected for another taxon, and the correct (or modern) usage follows after it.
Agujaceratops Lucas, Sullivan & Hunt, 2006
Ajkaceratops Ősi, Butler & Weishampel, 2010
Albertaceratops Ryan, 2007
Anchiceratops Brown, 1914
Archaeoceratops Dong & Azuma, 1997
Arrhinoceratops Parks, 1925
Auroraceratops You, Li, Ji, Lamanna & Dodson, 2005
Avaceratops Dodson, 1986
Bagaceratops Maryańska & Osmólska, 1975
Bainoceratops Tereschenko & Alifanov, 2003
Brachyceratops Gilmore, 1914
Breviceratops Kurzanov, 1990
Coahilaceratops Loewen, Sampson, Lund, Farke & McDonald, 2010
Ceratops Marsh, 1888
Diabloceratops Kirkland & DeBlieux, 2010
Diceratops Hatcher, 1905 – npo: Diceratops Förster, 1868
Eoceratops Lambe, 1915
Eotriceratops Wu, Brinkman, Eberth & Braman, 2007
Gobiceratops Alifanov, 2008
Graciliceratops Sereno, 2000 [n4]
Helioceratops Jin, Chen, Zan & Godefroit, 2009
Kulceratops Nessov, 1995
Lamaceratops Alifanov, 2003
Leptoceratops Brown, 1914
Liaoceratops Xu, Makovicky, Wang, Norell & You, 2002
Medusaceratops Ryan, Russell & Hartman, 2010
Microceratops Bohlin, 1953 – npo: Microceratops Seyrig, 1952
Mojoceratops Longrich, 2010
Montanoceratops Sternberg, 1951
Nedoceratops Ukrainsky, 2007 – nrn: Diceratops Förster, 1868
Ojoceratops Sullivan & Lucas, 2010
Pentaceratops Osborn, 1923
Platyceratops Alifanov, 2003
Prenoceratops Chinnery, 2004
Proceratops Lull, 1906 – nrn: Ceratops Marsh, 1888 [n3]
Protoceratops Granger & Gregory, 1923
Sinoceratops Xu, Wang, Zhao & Li, 2010
Tatankaceratops Ott & Larson, 2010
Triceratops Marsh, 1889
Turanoceratops Nessov & Kaznyshkina vide Nessov, Kaznyshkina & Cherepanov, 1989
Udanoceratops Kurzanov, 1992
Xuanhuaceratops Zhao, Cheng, Xu & Makovicky, 2006
Yamaceratops Makovicky & Norell, 2006
Zuniceratops Wolf & Kirkland, 1998
I will not list other ceratopsian names here, but the remaining nearly 30 names are certainly worth attention, along with those above, and I may eventually get to a review on them (focusing on various things such as nomenclature, the problem of the nomen dubium, and evolution of the dental series in Ceratopsia along with their bite, and whatever else comes along). For now, suffice to say that a disparity of almost 40 to almost 30 names represents a 2/3 majority of ceratopsian taxa with “ceratops” in their name. This, when it comes to dinosaurs at least, is an unparalleled taxonomic trend. I will also not list the references for the names above yet. I will add them in later in a further section below.
 Marsh, O. C. 1888. A new family of horned Dinosauria, from the Cretaceous. American Journal of Science (series 3) 36:477-478.
 Dodson, P. 1996. The Horned Dinosaurs. (Princeton University Press, Princeton.)
 Dodson, P. & Currie, P. J. 1990. Neoceratopsia. p.593-618 in Weishampel, Osmólska & Dodson (eds.) The Dinosauria. (University of California Press, Berkeley.)
 Dodson, P., Forster, C. A. & Sampson, S. D. 2004. Ceratopsidae. p.494-513 in Weishampel, Osmólska & Dodson (eds.) The Dinosauria (second edition). (University of California Press, Berkeley.)
 Penkalski, P. & Dodson, P. 1999. The morphology and systematics of Avaceratops, a primitive horned dinosaur from the Judith River Formation (Late Campanian) of Montana, with the description of a second skull. Journal of Vertebrate Paleontology 19(4):692-711.
 Dodson, P. 1986. Avaceratops lammersi: a new ceratopsid from the Judith River Formation of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia 138(2):305-317.
 Trexler, D. & Sweeney, F. G. 1995. Preliminary work on a recently discovered ceratopsian (Dinosauria: Ceratopsidae) bonebed from the Judith River Formation of Montana suggests the remains are of Ceratops montanus Marsh. Society of Vertebrate Paleontology, Abstracts. Journal of Vertebrate Paleontology 15(supp. to 3):57A
[n1] [Keratops = keratos + ops]. Κερατος in Greek meant “horned,” as derived from κερας (simply, “horn, beak”); ωψ
meant “face, eye” and had a general reference to the facial region of the head. Combined, they mean literally “horned face.”
[n2] Asiaceratops salsopaludalis Nessov & Kaznyshkina vide Nessov, Kaznyshkina & Cherepanov, 1989 was erected for extremely fragementary material that does not appear significantly ceratopsian, although this has never been rigorously tested.
[n3] Proceratops Lull, 1908 was named on the basis of the belief that Ceratops Marsh, 1888 was preoccupied by Ceratops Rafinesque, 1815; however, the latter name was published in a list [of avian genera] but never formally used or describing any specimen, and as such is a nomen nudum.
[n4] Graciliceratops Sereno, 2000 was named for Microceratops sulcidens (Bohlin, 1953) under the opinion that Micerceratops gobiensis (also in Bohlin, 1953), the type species, was a nomen dubium; Sereno, suggesting that Microceratops sulcidens, was far more diagnostic, separated the two taxa into different “genera.” This is another practice regarding nomina dubia I will eventually get to.