A Grammatical Dictionary of Botanical Latin

-ceros,-otis (s.m.III); in Gk. comp. '-horned:' the ending –ceros,-otis derives from the Gk. adjective keroeis, -oessa contr. oussa, oen (keras) ‘horned’ (Liddell & Scott); see -ceras,-atis (s.n.III);

        Singular                 Plural   
Nom.   rhinoceros (s.m.III).  rhinocerotes   
Gen.   rhinocerotis           rhinocerotum   
Dat.   Rhinoceroti            rhinocerotibus   
Acc.   Rhinocerotem           rhinocerotes   
Abl.   Rhinocerote            rhinocerotibus

Family Rhinocerotidae.

Rhinoceros unicornis; R. sondaicus

Rhinoceros,-otis (s.m.III) unicornis, abl.sg. Rhinocerote unicorni, the rhinoceros [> Gk. rhinokerOs,-Otos (s.m.III), “the rhinoceros or Nose-horn; a wild bull” (Liddell & Scott) > rhis, nose + [kerOs] > keras, ‘horn’].

Anthoceros, Dendroceros, Macroceros, Phaeoceros.

NOTE: Diceros,-otis (s.m.III): the name of a (fossil) Rhinoceros.

NOTE: apparently all nouns ending in –ceros,-otis are masculine, on analogy with Rhinoceros.

NOTE: the ending –ceros,-otis derives from the Gk. adjective keroeis, -oessa contr. oussa, oen (keras) ‘horned’ (Liddell & Scott) as suggested by Paxton:

- Anthoceros, from anthos, a flower, and keroeis, horned; alluding to the horn-like form of the theca. Jungermanniaceae (Paxton).

NOTE: Generic names of Greek origin ending in -os (omega sigma), usually declined by analogy with rhinoceros (Stearn).

Helicodiceros, “spirally 2-horned, probably referring to the 2 lateral leaflets of each leaf” (Bailey 1949)) [helico + di + ceros].

"Although the pre-Linnaean authors Micheli and Dillenius used the genitive singular Anthoceri, post-Linnaean authors, among them Richard Spruce, have preferred the genitive singular Anthocerotis, hence the family name Anthocerotaceae. Anacampseros is similarly declined" (Stearn).

Epithets in the following examples are probably all nouns in apposition.

(Orchidaceae) Disperanthoceros anthoceros; Ceratobium strepsiceros; Crepidium rhinoceros; Epidendrum tetraceros; Eria rhinoceros; Liparis Monoceros; Rhinocerotidium rhinoceros; Trichoceros platyceros.