I read on Wikipedia that Japanese geta originated in China, where they had a different construction and were worn through a few periods. I would love to learn more about the versions worn in China! Have you seen any pictures or information about them?
Yes, geta (or muji/木屐 in Chinese) does have a long history in China. Historians speculate it was likely around the Tang Dynast when the muji entered Japan due to the large economic and cultural exchanges between the two countries during this period (a lot of Tang Dynasty artefacts in Japan today were also exported there during this period).
The earliest muji artefact found in China of muji is from over 3000 years ago, at the Cihui ruins (慈湖遗址):
You can see there's 5 holes on the shoe, rather than the 3 holes on the Japanese geta today. Here's a Japan vs Chinese geta/muji in comparison (left Chinese, right Japan):
The Chinese one wraps all the way around the foot whereas the modern, Japanese geta has just the two straps at the front (I don't know if the geta in Japan went through any changes throughout history or if it had always been like that).
There are also some that have just a single, wide band across the front (like a slip-on sandal today), or one strap across the front where the toes are, and one near the back for better support.
In Chinese history, this type of footwear was mostly worn around the Han/Weijin period, although there are records of it being used in later dynasties as well.
These pairs are from the Three Kingdom period (late Han), unearthed from the Zhuran tomb (三国，东吴，朱然墓). They're unique because of the lacquer coating painted on top.
These three are from the Six Dynasty Museum (六朝博物馆) in Nanjing (Six dynasty = from Three Kingdom to the end of the North/South Dynasty (东吴、东晋、宋、齐、梁、陈)).
These two sets were unearthed from the Xuancheng Western Jin tomb (宣城西晋墓)
The muji was categorized into 3 types:
Lianchi (连齿) = the two wooden 'teeth' at the bottom of the muji and the top piece is all carved using one piece of wood
Yinmao (阴卯) = the two wooden 'teeth' at the bottom are separate from the top piece
Pingdi (平底) = no wodden 'teeth' at the bottom, like a platform or wedged heel:
In Western Han 202 BC-8 AD) there was a book called:
西汉史游 《急就篇》 (Western Han Shiyou <Jijiu Chapter>)
This book was kind of like an encyclopedia and covered things like animals, plants, food, clothing, medicine, court positions, instruments, along with other topics. It was used to teach Chinese characters and also spread information (like a textbook used today).
In this book, it mentions the muji.
Later during the Tang Dynasty (618 AD - 917 AD) the court official Yan Shigu (颜师古) added to the book that:
"屐者，以木为之，而施两齿，所以践泥"
("The ji [muji], is made from wood, has two teeth, so can step on mud")
