The wild turkey (Meleagris gallopavo) is one of the most recognizable species of bird. The bird is one of those foundational species of modern North American wildlife, found everywhere from California and Mexico to Canada and Maine. The domestic turkey (M. g. domesticus) is also very well known, commonly consumed during holidays and in sandwiches everywhere. Its rarer cousin, the ocellated turkey (M. ocellata), is found in a small pocket of land overlaying parts of the Yucatán peninsula, Belize, and Guatemala. Additionally, a few other species of Meleagris are known: M. californica, M. leopoldi, M. progenes, M. anza, M. crassipes, M. alta, and M. tridens, though some of them may be synonymous. These trail-blazing species all went extinct during the Pliocene and Pleistocene epochs.

However, there is another known turkey that helps to elucidate the origins of its modern-day relatives. Rhegminornis calobates represents the earliest-known turkey, from the earliest part of the Miocene epoch over 23 million years ago. The original specimen, a lower leg bone, was found in northern Florida in the Thomas Farm locality near Gainesville. This specimen was scientifically described in 1943 by Alexander Wetmore, one of the preeminent ornithologists of the 20th century. While there exists no readily-available etymological meaning for the name, one interpretation of the generic name may be from Greek signifying “small tear bird.” Meanwhile, “calobates” may either refer to rope dancing, perhaps to emphasize that it is based on a leg bone, or to another name for a type of ground cuckoo.

 Wetmore’s initial interpretation of the fossil was as a wading bird related to the modern jacana. However, research by Storrs Olson and John Farrand, Jr cemented R. calobates firmly as a turkey relative within the family of Phasianidae, which also includes pheasants and grouse. According to their 1974 paper, "Rhegminornis restudied", the lower leg bone- known in birds as a tarsometatarsus- was a bit wider than in jacana birds, as well as having a generally different appearance. First, they were able to agree these characteristics to Galliformes in general,

which is the clade of animals including Phasianidae, quails, guineafowl, and a few other groundbirds. Secondly, they compared the original leg bone specimen of R. calobates with the same bone from a modern female M. gallopavo, finding many characteristics shared between the two. Two other specimens of the Miocene turkey were also studied by the team.

One big difference between modern turkeys and R. calobates is the size; as shown by the leg fossil, modern turkeys dwarf their prehistoric cousins. Fossil turkeys have demonstrated a gradual increase in size, all beginning with the tiny turkey. However, it still may have filled a similar niche living in ancient northern Florida. At that time, central and southern Florida was primarily marine, with northern Florida being filled with some grassland and sparse woods. Modern wild turkeys usually rely on open fields but also a good amount of wooded coverage for their territory. The early Miocene of northern Florida likely had an adequate habitat for the use and development of

traits that have persisted through to today’s turkeys from Rhegminornis. This environment also created favorable conditions for R. calobates’ Miocene neighbors. From the locality of the holotype leg specimen, Thomas Farm, a plethora of ancient animals have been found. Among them were extinct species of alligators, horses, camels, rhinoceros, and much more.

R. calobates established itself as the earliest known turkey, wandering Floridian grasslands over 23 million years ago. Key shared traits in its lower leg bones help to place the small bird definitively within turkeys as a group. Indeed, these key characteristics helped to connect the fossil to modern turkeys in a way its tiny stature could not. Nevertheless, Rhegminornis represents a small yet important early step in one of North America’s most remarkable and influential birds.

Sources:

“Florida Fossils: Miocene Epoch.” Florida Museum, 11 Apr. 2022, www.floridamuseum.ufl.edu/exhibits/blog/florida-fossils-miocene-epoch/.

“Florida Miocene Painting by Bob Beach.” Florida Museum, 5 Sept. 2023, www.floridamuseum.ufl.edu/exhibits/blog/florida-miocene-painting-by-bob-beach/.

“Florida Museum Vertebrate Paleontology Collection.” Florida Museum, 2025, specifyportal.floridamuseum.ufl.edu/vp/.

“Fossils of the Coastal Plain.” Earth@Home, 

earthathome.org/hoe/se/fossils-cp/.

Hinke, Veronica. “Talking Turkey: Forest Service and National Wild Turkey Federation Bringing Back

Native Turkey Habitats.” USDA, 21 Nov. 2017,
www.usda.gov/media/blog/2017/11/21/talking-turkey-forest-service-and-national-wild-turkey-federation-bringing.

Olson, Storrs L, and John Farrand. “Rhegminornis Restudied: A Tiny Miocene Turkey.” The Wilson

Journal of Ornithology, vol. 86, no. 2, 1 Jan. 1974, pp. 114–120,
www.jstor.org/stable/4160466?seq=1.

“Thomas Farm.” Florida Museum, 2016,
www.floridamuseum.ufl.edu/florida-vertebrate-fossils/sites/thomas-farm/.

“Wild Turkey Habitat Management - NYSDEC.” NYSDEC,
dec.ny.gov/nature/animals-fish-plants/wild-turkey/habitat-management.