Speaking of traditional tanto, "tanto" is not a blade profile. It refers to the length. Blade weapon of a certain length is a tanto. Longer than a tanto is a wakizashi, and longer than that is a katana. And all of the aforementioned blades can come in many different blade profile. In tanto, the most common profile is hira-zukuri, literally means "without ridge line." The second most common blade profile for tanto is shobu-zukuri. The blade profile most associated with katana, shinogi-zukuri, is rarely seen in tanto size. When it is seen, it is often the result of a broken katana or wakizashi that was remade into a tanto.
None of the Americanized tanto looks anything like traditional tanto. Even the modern version that resemble kiriha-zukuri makes little sense. The Japanese abandoned that profile very early on because it was inferior to other profiles. Kiraha-zukuri is an exact copy of the Chinese Tang Dynasty dao. The Chinese abandoned it as well. Why adopt a blade profile that the original creators deemed inferior and abandoned?
FYI, a tanto without a guard (tsuba in Japanese) is an aikuchi. A very short tanto is a kwaiken, without guard as well. All the aforementioned short blades can be curve or straight.