Giraffomorpha is a clade of
pecoranruminants containing the superfamilies
Palaeomerycoidea (Palaeomerycidae) and
Giraffoidea (
Giraffidae,
Prolibytheriidae and
Climacoceratidae), of which the
giraffe and
okapi of the Giraffidae are the only extant members of the once-diverse clade as a result of a decline in diversity after the Miocene as a result of declines in temperatures. The clade is defined by the presence of
ossicones, suggesting that the feature was developed as a result of basal, related evolutions between the two superfamilies rather than as an instance of
parallel evolution. Giraffomorpha is also characterized by a lack of articular fossettes (hollows) in
metatarsal bones III-IV.[1][2][3]
The position of the giraffomorphs Propalaeoryx of the Miocene of Africa and the insular Sardomeryx of the Miocene of
Sardinia are not completely resolved but are recently suggested to be within the Palaeomerycoidea without being situated within the Palaeomerycidae family itself.[1][4][5]
^Mennecart, Bastien; Zoboli, Daniel; Costeur, Loïc; Pillola, Gian Luigi (2018). "On the systematic position of the oldest insular ruminant Sardomeryx oschiriensis (Mammalia, Ruminantia) and the early evolution of the Giraffomorpha". Journal of Systematic Palaeontology. 17 (8): 691–704.
doi:
10.1080/14772019.2018.1472145.