Dinosaurs by Parcel Post.

It's one of the strangest things the mail does. It's also the most chicken thing possible: an animal so useful that people built the mail system around it, and so tough it survives being posted.

Chickens are probably the most common bird on Earth. They're also the closest thing most people will ever get to touching a dinosaur. And they come in breeds so strange they look made up: black inside and out, fluffy like a cat, tails metres long, eggs the colour of the sky.

Birds are the one branch of dinosaurs that survived. A chicken's feet are covered in scales. Its wishbone, hollow bones and three forward toes are all dinosaur parts, and you can see them on a dinner plate.

In 2007 scientists pulled tiny fragments of protein out of a 68-million-year-old T. rex bone and compared them with living animals. Of the seven protein pieces they read, three matched chicken collagen. The team said the set as a whole looked closest to chicken.

The palaeontologist Jack Horner pushed the idea further in his book How to Build a Dinosaur (2009): the "chickenosaurus", a plan to switch on old dinosaur traits like tails and teeth in a chicken embryo. Nobody has hatched one.

Every chicken descends mainly from the red junglefowl, a wild bird of Southeast Asian forests. A 2022 study of chicken bones from more than 600 sites found that the earliest clearly domestic chickens turn up at Ban Non Wat in central Thailand, around 1650 to 1250 BCE. That's about 3,500 years ago.

The likely reason: rice and millet. Farmers stored grain, junglefowl came for the free food, and they never left. Chickens may have been kept for cockfighting and as special animals long before anyone thought of them as dinner.

PLATE II. Hens and roosters photographed for the Queensland government, around 1900.

Fast-forward to America. The Post Office started its parcel post service in 1913. Around the end of that decade, it began accepting live day-old chicks, as long as they could reach their destination within 72 hours.

A small-town banker in Webster City, Iowa named Murray McMurray had started selling chicks in 1917. Mail order meant he could sell far beyond his bank's customers. Murray McMurray Hatchery still ships chicks by mail today.

Chicken shows are serious. The American Poultry Association was founded in 1873, and in 1874 it published the first Standard of Perfection: the rulebook for what every breed is supposed to look like, down to the comb, the feather colour and the angle of the tail. Judges still use it.

PLATE IV. Barred Plymouth Rocks, from The Poultry Manual: a complete guide for the breeder and exhibitor, 1911.

Roosters have rules too. A 2013 study in Japan found that roosters crow on an internal clock, not just at the first light. A follow-up found that in a flock, the top-ranked rooster crows first each morning, and the others wait their turn.