Related by context. Frequent words. (Click for all words.) 57 Ardipithecus ramidus 57 pre Incan 56 flint tools 56 Inca Empire 55 Palaeolithic 55 Step Pyramid 55 microfossils 55 limestone cave 55 fossils 54 middens 54 Namib Desert 54 lake sediments 54 Radiocarbon dating 54 horned dinosaur 53 Mesolithic 53 stromatolites 53 Neandertal 53 dinosaur footprints 53 Abydos 53 foraminifera 52 Archaean 52 anthropoids 52 igneous rock 52 lava tubes 52 Neolithic 51 royal tombs 51 ancient Mesopotamia 51 Inca empire 51 fossilized remains 51 radiocarbon dated 51 hominid 51 prehistoric 51 Late Cretaceous 51 hominins 51 Jurassic Period 51 #BC [003] 51 Lapita 50 dinosaur fossils 50 alluvial deposits 50 feathered dinosaurs 50 marine sediments 50 Harappan 50 Columbian mammoth 50 limestone caves 50 prehistory 50 Harappa 50 Uruk 50 Omo River 50 archaeologically 50 Paleocene 50 ancient 50 Herodium 50 coprolites 50 hominin 50 haematite 50 Nigersaurus 50 Dmanisi 50 trackways 49 archeological 49 faunal 49 burial mounds 49 classical antiquity 49 ancient tombs 49 excavated 49 Ancient Egyptians 49 sedimentary rock 49 relict 49 Burgess Shale 49 dinosaur fossil 49 sauropod 49 cypress swamp 49 archaeologists 49 Elamite 49 Ardipithecus 49 archaeological finds 49 Homo erectus 49 landform 49 Amenhotep III 49 Indohyus 49 alluvium 49 archaeological 49 Tiktaalik 49 ancient civilization 49 Incan 48 Fertile Crescent 48 Australopithecus afarensis 48 Great Rift Valley 48 Oetzi 48 theropod 48 ocher 48 ancient Babylon 48 sugar cane plantation 48 interglacial period 48 Hatra 48 arid lands 48 Australopithecus 48 Amazonian rainforest 48 Fossilized 48 midden 48 calcareous 48 excavations