Safari Park, this is a very sad, and a alarming thread too, thank you for posting it!!!, a few of these species such as the Moroccan dorcas gazelle (Gazella dorcas massaesyla), Burmese muntjac (Muntiacus muntjak curvostylis), and Sindh wild goat (Capra hircus blythi) I wasn't aware that they were ever held in North American zoos until I found this thread ? Which zoos had them ?
Also I always enjoy reading your posts, I very much agree with every single one of them, they are quite thought provoking...
Also here are some hoofstock species missing from your lists that are gone from or are extremely rare in North American zoos, some of these species date back as early as the 1920s, but I guarantee you that if you were to combine our lists, it would be far from complete regarding how many hoofed mammals are gone or almost gone from North American zoos, here is the list I compiled:
Jentinks duiker
Hirola
Black fronted duiker
Visayan spotted deer
Cokes hartebeest
Maral
British red deer
Carpathian red deer
Cottons oribi
Roberts gazelle
Marco polo argali
Marsh deer
Chaco pampas deer
Manchurian wapiti
Yucatan brown brocket
Chinkara gazelle
Mountain gazelle
Isabelline gazelle
Aders duiker
Bohor reedbuck
Tsessebe
Dibatag
White eared kob
Burmese banteng
Lichtensteins hartebeest
Water chevrotain
Pygmy hog
Javan warty pig
Wild yak
Spanish ibex
Red goral
Giant forest hog
Indonesian wild boar
Newfoundland caribou
Osborns caribou
North andean huemul
Cape grysbok
Bokharan argali
Stones sheep
Fannin sheep
Abbotts duiker
Tiang
Kabul markhor
Astor markhor
Philippine brown deer
Nubian wild ass
Siberian roe deer
Central african savanna buffalo
Sri lankan sambar
Alpine chamois
Saiga
Peary caribou
Altai argali
And I can go on and on...