"discrimination against certain animals based on assumption of human superiority," first attested 1975 in Richard D. Ryder's "Victims of Science," from species + -ism.
Entries linking to speciesism
species n.
late 14c., in logic, "a of individuals or things," from Latin species "a particular sort, kind, or type" (opposed to genus), originally "a sight, look, view; outward appearance, shape, form," a derivative of specere "to look at, to see, behold" (from PIE root *spek- "to observe"). In English it is attested from 1550s as "appearance, outward form."
Latin species "a sight; outward appearance" had many extended senses, including "a spectacle; a mental appearance, an idea or notion;" also "semblance, pretext; manner, fashion; display, beauty; a likeness or statue; reputation, honor." Typically it was used in passive senses. Also compare spice (n.).
In Late Latin, in logic and legal language, it acquired the meaning "a special case," especially (as a translation of Greek eidos) "a included under a higher class; a kind; a sort; a number of individuals having common characteristics peculiar to them." The notion (as Lewis & Short puts it) is "The particular thing among many to which the looks are turned."
The English word is attested from 1560s as "a distinct (of something) based on common characteristics." The specific use in biological sciences in reference to groups of living things recognizably distinct from all others by their inherited characteristics is from c. 1600. Endangered species is attested by 1964.
-ism
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.