It appears in the fossil record around 30 million years ago and may be the earliest member of the second great subfamily, the Borophaginae, the bone-crushers.
它出现在大约 3000 万年前的化石记录中，可能是第二大亚科 Borophaginae（碎骨动物）的最早成员。
Borophaginae
原声例句
PBS地球-动物趣闻
中文百科
恐犬亚科
![](/Images/godic/202501/01/Aelurodon_stirtoni4938.jpg")
恐犬亚科（学名：Borophaginae）是已灭绝一类犬科，是北美洲的特有种，生存于4000-250万年前的渐新世至上新世。
恐犬亚科是从古犬亚科演化而来，体型上更为大型，一些恐犬亚科像现今的狮般大，有些则像浣熊或郊狼。牠们占有新生代北美洲多个生态位，由细小的杂食性至强壮的肉食性都有。
恐犬亚科一般都有强壮及像鬣狗的牙齿及颚骨，而且化石很丰富及广泛分布。牠们有可能是生态系统中的顶级掠食者。种系发生学显示恐犬亚科是高度多样化的。
英语百科
Borophaginae 恐犬亚科
![Phylogeny of borophagines by R.L. Tedford, 1977](/Images/godic/202501/01/Wang_Borophagine_Construct4938.png")
![Fluctuation of species within Canidae over 40 million years](/Images/godic/202501/01/Canidae_Species_Divesity4938.png")
![](/Images/godic/202501/01/Borophagini_range4938.png")
The subfamily Borophaginae is an extinct group of canids called "bone-crushing dogs" that were endemic to North America during the Oligocene to Pliocene and lived roughly 36—2.5 million years ago and existing for about 33.5 million years.
- pregnancy associated plasma protein D
- pregnancy associated with acute appendicitis
- pregnancy associated with appendicitis
- pregnancy associated with blood disease
- pregnancy associated with cardiac disease
- pregnancy associated with cardiovascular disease
- pregnancy associated with diabetes
- pregnancy associated with hysteromyoma
- pregnancy associated with infectious hepatitis
- pregnancy associated with osteomalacia
- pregnancy associated with ovarian tumor
- pregnancy associated with pulmonary tuberculosis
- pregnancy associated with pyelonephritis
- pregnancy associated α2 glycoprotein
- pregnancy associated α2glycoprotein
- pregnancy association glycoprotein
- pregnancy asthma
- pregnancy at term
- Pregnancy beyond 42 weeks of gestation
- Pregnancy,Cardiovascular Complications
- pregnancy ceased
- pregnancy cell
- pregnancy cells
- pregnancy check
- pregnancy cohort study