Pronolagus

…General term for mammals of the Palaeolaginae subfamily of the order Lagomorpha. They appeared in the late Eocene (about 40 million years ago) and flourished in Asia and North America from the Oligocene to the Miocene. Thirteen genera were known, but they were almost extinct when they were deprived of their habitat by the Lagomorpha subfamily that appeared at the end of the Pliocene and flourished in the Pleistocene. Today, only three genera and five species remain: the Amami rabbit Pentalagus furnessi (illustration), three species of the Japanese red rabbit Pronolagus (English name red rabbit), and the Mexican rabbit Romerolagus diazi (English name volcano rabbit). All of them have a distinctive structure of the third premolar of the lower jaw, and when viewed from the biting surface, the tooth has deep notches on both the inside and outside, forming a 'ro' shape, which differs from the 'ko' shape of the Lagomorpha subfamily. …

*Some of the terminology explanations that mention "Pronolagus" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…ウサギ目ウサギ科ムカシウサギ亜科Palaeolaginaeの哺乳類の総称。始新世後期(約4000万年前)に出現し，漸新世から中新世にかけてアジアと北アメリカで栄え，13属が知られたが，鮮新世末に出現し，洪積世に栄えたウサギ亜科のものに生活の場を奪われてほとんど絶滅し，今日ではアマミノクロウサギPentalagus furnessi(英名Ryukyu rabbit)（イラスト），3種のアカウサギPronolagus(英名red rabbit)，およびメキシコウサギRomerolagus diazi(英名volcano rabbit)の3属5種が残存するのみである。いずれも下あごの第3前臼歯（ぜんきゆうし）の構造に著しい特徴がみられ，その歯を咬面（こうめん）から見ると内側と外側から深い切れ込みがあり〈呂〉の字形を呈し，〈コ〉の字形のウサギ亜科のものと異なる。…

※「Pronolagus」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報