龙担为真马动物群化石的代表性产地。该化石群主要产出于早更新世午城黄土中，上化石层黄土层，铁锰包膜较集中，少量菌丝，5 层结核，有零星小化石，有的层较硬，有的较疏松，厚 4.9m。下化石黄土层，表面干燥坚硬，少量铁锰斑点，少量蜗牛化石，根虫孔，结核发育，厚 3.7m。上化石层年龄为 1.9Ma B.P, 下化石层位年龄为 2.25Ma B.P。真马动物群化石产地目前发现的化石有 33 种，已知的种类包括啮齿类的东方高冠松鼠（Aepyosciurus orientalis）、小旱獭（Marmota parva）、河狸（Castor sp.）、甘肃模鼠（Mimomyscf. gansunicus）、灞河鼠（Bahomys sp.），兔形类的矮脚丝绸兔（Sericolagus brachypus），灵长类的安氏猴（Macaca cf. anderssoni）、甘肃副长吻猴（Paradolichopithecus gansuensis），食肉类的鸡骨山狐（Vulpes chikushanensis）、德氏犬（Canis teilhardi）、龙担犬（C. longdanensis）、短头犬（C. brevicephalus）、拟震旦豺（Sinicuon cf. dubius）、硕獾鼬（Eirictis robusta）、德氏狗獾（Meles teilhardi）、进步豹鬣狗（Chasmaporthetes progressus）、桑氏硕鬣狗（Pachycrocuta licenti）、河南斑鬣狗（Crocuta honanensis）、锯齿虎（Homotherium crenatidens）、泥河湾巨颏虎（Megantereon nihowanensis）、临夏西瓦猎豹（Sivapanthera linxiaensis）、古中华虎（Panthera palaeosinensis）、德氏猫（Felis teilhardi）、山西猞猁（Lynx shansius），奇蹄类的中国长鼻三趾马（Hipparion sinense）、埃氏马（Equus eisenmannae）、泥河湾披毛犀（Coelodonta nihowanensis）、黄昏爪兽（Hesperotherium sp.），偶蹄类的野猪（Sus sp.）、龙担日本鹿（Nipponicervus longdanensis）、步氏羚羊（Gazella cf. blacki）、短角丽牛（Leptobos brevicornis）和秀丽半牛（Hemibos gracilis）等。
This locality is the representative origin of the equus fauna fossils. This group of fossils is primarily produced in the early Pleistocene Wucheng loess. The upper fossil layer is loess-like material, concentrated iron and manganese coating, a few hyphae, 5 layers of nodules, and scattered small fossils. Some layers are hard and some are looser with a thickness of 4.9m. The lower fossil layer is: yellow earthy material, dry and hard surface, a few iron-manganese spots, a few snail fossils, root wormholes, and nodules, 3.7m thick. The age of the upper fossil layer is 1.9 Ma, and the lower is 2.25 Ma. There are 33 species of fossils discovered so far. The known species of Hezheng Equus fauna include Aepyosciurus orientalis, Marmota parva, Castor sp., Mimomys cf. gansunicus, and Bahomys sp.of rodents, Sericolagus brachypus of Lagomorph, Macaca cf. anderssoni and Paradolichopithecus gansuensis of Primates ， Vulpes chikushanensis, Canis teilhardi, C. longdanensis, C. brevicephalus, Sinicuon cf. dubius, Eirictis robusta, Meles teilhardi, Chasmaporthetes progressus, Pachycrocuta licenti,Crocuta honanensis, Homotherium crenatidens, Megantereon nihowanensis, Sivapanthera linxiaensis, Panthera palaeosinensis, Felis teilhardi and Lynx shansius of Carnivora, Hipparion sinense, Equus eisenmannae, Coelodonta nihowanensis 9and Hesperotherium sp.of Perrisodaetyla, Sus sp., Nipponicervus longdanensis, Gazellacf.blacki,Leptobos brevicornis and Hemibos gracilis of Artiodactyla.
