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293genannt und hinzu kommen noch die Autapomorphien. Allein zum ThemaDentition könnten noch mehrere weitere "characters out of phase" ergänzt werden(vgl. Wang 1994, pp. 22/23). 553Fazit zur Ableitung der Caniden-Unterfamilie Hesperocyoninae von denMiacidae: Die in der Originaldarstellung durchgezogene dünne Linie, die diezahlreichen postulierten Bindegleider repräsentieren soll, existiert nur auf demPapier. Hypothese: Sowohl die Miaciden als auch die Herperocyoninaerepräsentierten jeweils einen gesonderten Grundtyp.22.2 Borophaginae und StammbäumeWie steht es nun mit der Ableitung der nächsten Unterfamilie der Caniden, derBorophaginae 554 von den Hesperocyoninae? Worum handelte es ich bei denBorophaginae? Wikipedia (2013):"The subfamily Borophaginae is an extinct group of canids called "bone crushing dogs" that wereendemic to North America during the Oligocene to Pliocene and lived roughly 36—2.5 million years agoand existing for approximately 33.5 million years.Origin. The Borophaginae apparently descended from the subfamily Hesperocyoninae. The earliestand most primitive borophagine is the genus Archaeocyon, which is a small fox-sized animal mostly foundin the fossil beds in western North America. The borophagines soon diversified into several major groups.They evolved to become considerably larger than their predecessors, and filled a wide range of niches inlate Cenozoic North America, from small omnivores to powerful, bear-sized carnivores such asEpicyon." 555Wang und Tedford 2008/2010, p. 36:"Very similar in size (less than 2 kg) and shape to Hesperocyon, species of Archaeocyon (from Greekarchae [ancient] and cyon [dog]) are the ancestors of all other borophagines. Fossils of Archaeocyonalso compose some of the earliest records of the subfamily Borophaginae.”"…some of the earliest reords”? Wir stoßen an dieser Stelle auf das gleichePhänomen wie oben für Hesperocyon und Prohesperocyon beschrieben: eine vonArchaeocyon evolutionär abgeleitete stark spezialisierte, vermutlichwüstenbewohnende Form, Otarocyon, tritt im Fossilbericht mehr als 2 Millionen553 Zum Thema "characters out of phase” ein paar weitere Punkte nach Xiaoming Wang, 1994, pp. 22 und 23: "Corresponding to the longrostrum, the upper premolars are long and slender, and there are rather wide diastemata between the premolars. The P1 is single-rooted.The P1-2 have a single main cusp and only P3 has a very small posterior accessory and cingular cusps, a derived condition over miacids, whichmostly lack the accessory cusp. The P4 has a large protocone that protrudes in front of the anterior border of the paracone, a primitivecharacter seen in most miacids. A vague anterior cingulum is present on P4, and a lingual cingulum is seen only toward the posterior end of thetooth at the base of the metastyle. The outline of M1 is more like Miacis than Hesperocyon; this primitiveness is mainly reflected in its large,transversely oriented parastyle, which displaces the protocone toward the lingual side, and in its narrow, crestlike internal cingulum in contrast toa more swollen cingulum in Hesperocyon. The M1 of Prohesperocyon, however, is more derived in its relatively reduced parastyle. A notchbetween the parastyle and paracone is lost in Prohesperocyon; this notch is present in most miacids and Procynodictis. The anteriorsegment of the internal cingulum is greatly reduced so that the internal cingulum begins to assume a posterolateral configuration, as inHesperocyon. The M1 thus has a transversely elongated appearance, leaving room for a larger trigon basin than in Hesperocyon. The M1paraconule (protoconule) and metaconule are also more distinct than in Hesperocyon. The M2 is relatively smaller than in Hesperocyon. Apeculiar dental feature of P. wilsoni is its greatly reduced metacone of M2 such that the paracone entirely dominates the metacone. Themetacone is no more than an indistinct ridge, lacking a labial cingulum. Such a condition of metacone reduction is shared only with Procynodictisvulpiceps Wortman and Matthew (= Miacis gracilis Clark) of North American Unitan (see Wang and Tedford, 1994) and is not seen in morederived canids. No M3 is present, although the present sample (one) is obviously too small to exclude the possibility of its presence in someindividuals since occasional specimens of H. gregarius retain it.” […..] "In particular, the M1 of Prohesperocyon still retains a rather largeparastyle (although reduced compared to miacids) and an unenlarged internal cingulum, characters also found in Mustelavus. The overall dentalmorphology and the skull structure are also very similar between the two. While remaining obscure in its phylogenetic position, Mustelavusexhibits some basal musteloid features, as suggested by Clark (1937). Some of these features can be used to distinguish Mustelavus fromprimitive canids: poor development of accessory cusps on premolars, presence of a cingulum around the premolars, and low trigonid cusps ofm2."554 "The genus Borophagus (from Greek boros [voracious) and Latin phago [eating) is the name bearer of the entire subfamily Borophaginae... "Wang und Tedford 2008/2010, p. 46.555 http://en.wikipedia.org/wiki/Borophaginae (Zugriff 14. 4. 2013)