Since January 2020, Elsevier has created a free COVID-19 resource center with English and Mandarin information on the novel coronavirus. The center is hosted on Elsevier Connect, providing access to research for unrestricted reuse. The article discusses the natural hosts and zoonotic sources of four endemic human coronaviruses (HCoVs): HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1. These viruses contribute significantly to respiratory infections in humans. While their clinical symptoms resemble the common cold, their evolutionary histories and host associations offer insights into past pandemics. HCoV-NL63 and HCoV-229E may originate from bat reservoirs, while HCoV-OC43 and HCoV-HKU1 likely evolved from rodent-associated viruses. HCoV-OC43 may have originated from domestic animals like cattle or swine, with the bovine coronavirus possibly being an ancestor. New data suggest HCoV-229E may have originated from dromedary camels, similar to the MERS-CoV. This scenario parallels the current prepandemic host associations of MERS-CoV. The article also explores the evolutionary origins of these viruses, their potential zoonotic sources, and the role of intermediate hosts in their transmission. It highlights the importance of understanding viral evolution and host associations to predict and prevent future pandemics. The study emphasizes the role of bats and rodents as potential primordial hosts for many coronaviruses, and the need for further research into the diversity and evolution of these viruses in various animal species.Since January 2020, Elsevier has created a free COVID-19 resource center with English and Mandarin information on the novel coronavirus. The center is hosted on Elsevier Connect, providing access to research for unrestricted reuse. The article discusses the natural hosts and zoonotic sources of four endemic human coronaviruses (HCoVs): HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1. These viruses contribute significantly to respiratory infections in humans. While their clinical symptoms resemble the common cold, their evolutionary histories and host associations offer insights into past pandemics. HCoV-NL63 and HCoV-229E may originate from bat reservoirs, while HCoV-OC43 and HCoV-HKU1 likely evolved from rodent-associated viruses. HCoV-OC43 may have originated from domestic animals like cattle or swine, with the bovine coronavirus possibly being an ancestor. New data suggest HCoV-229E may have originated from dromedary camels, similar to the MERS-CoV. This scenario parallels the current prepandemic host associations of MERS-CoV. The article also explores the evolutionary origins of these viruses, their potential zoonotic sources, and the role of intermediate hosts in their transmission. It highlights the importance of understanding viral evolution and host associations to predict and prevent future pandemics. The study emphasizes the role of bats and rodents as potential primordial hosts for many coronaviruses, and the need for further research into the diversity and evolution of these viruses in various animal species.