Ecology, Conservation and Management of Wild Pigs and Peccaries

Part I: Evolution, Taxonomy, and Domestication

2

perhaps three, species of collared peccaries (Gongora et al. 2006;

Groves & Grubb 2011).

Suoidea likely emerged in the Middle–Late Eocene of China

and Thailand (Tong & Zao 1986; Ducrocq et al. 1998; Liu 2001)

and subsequently diversified into various families including

extant Suidae and Tayassuidae represented by a number of

primitive forms (Pickford 1993; Wright 1993a, 1993b, 1998;

Orliac et al. 2010a). Although a great deal of our understanding

of suoid evolutionary history is based on dental morphology,

taxonomic difficulties persist in differentiating early Suidae and

Tayassuidae, so that some of their evolutionary relationships

remain unresolved (Liu 2001, 2003; Harris & Liu 2007; Prothero

2009; Orliac et  al. 2010a; van der Made 2010; Pickford 2012).

For instance, morphological studies show that extinct Old

World Tayassuidae form a distinct clade whereas New World

Tayassuidae appear to be paraphyletic, showing an unresolved

relationship with other primitive suoids from the Old World

(Orliac et al. 2010a). This has given rise to the hypothesis that

there were at least two events of colonization by tayassuids

from Asia into the Americas (Frantz et al. 2016), although this

ambiguity could be the result of limited sampling and/or dif-

ferent cranial characters used in relation to previous studies by

Wright (1993a, 1993b, 1998) (D. Prothero, personal communi-

cation). This debate has not been an impediment to estimating

that Suidae and Tayassuidae diverged from a common ances-

tor sometime during the Late Eocene (37–34 Ma) in South East

Asia, based on both morphological and DNA data (Ducrocq

1995; Randi et al. 1996; Ducrocq et al. 1998; Wright 1998; Orliac

et al. 2010a; Gongora et al. 2011a), and that they subsequently

dispersed into the Old World with Tayassuidae also migrating

into the New World as early as the Late Eocene as attested by the

presence there of the genus Perchoerus (Ducrocq 1995; Wright

1998; Harris & Liu 2007; Prothero 2009).

Suidae

Diversification and Dispersal

The earliest known fossil suid, Hyotherium, occurred in Early

Oligocene deposits on the Indian subcontinent (Orliac et  al.

2010a, 2010b). Throughout the Neogene, Suidae diversified into

approximately 20 genera, representing up to seven subfamilies,

including Suinae, which may have originated towards the end of

the Middle Miocene (11–10 Ma) (Pickford 1993; Harris & Liu

2007; Orliac et al. 2010a). Many genera of Suinae had emerged

by the beginning of the Pliocene including Porcula and Sus

(Hodgson 1847; Pilgrim 1926; Thenius 1970; Liu 2003; van der

Made et al. 2006). By many authors, all of the extant suid spe-

cies are classed as representatives of Suinae (Grubb 2005; Harris

& Liu 2007), with some debate in relation to Babyrousa as dis-

cussed below.

Fossil biochronologies indicate that six subfamilies of

Suidae, including Suinae, colonized Africa from Eurasia at least

six times during the Plio-Pleistocene (Pickford 2006). Suinae

dispersed into Africa from the Middle Miocene and became

the predominant and only subfamily among Suidae in this con-

tinent (Cooke 1978; Cooke & Wilkinson 1978; Harris 1983;

Bender 1992; White 1995; Kullmer 1999; Geraads 2004; Pickford

2006). The first fossil evidence of the African Suinae is the

genus Kolpochoerus, around the Miocene–Pliocene boundary

Figure 1.1 World map showing the natural distribution of extant Suidae in Africa, Asia, and Europe and Tayassuidae in the Americas. This is based on data

extracted from various sources including the IUCN Red List of Threatened Species homepage (www.iucnredlist.org/). Designed by Daniele Baisero of the Global

Mammals Assessment, University ‘La Sapienza’, Rome (Source: IUCN).

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