Byzantion, Thrace, Cow l. on dolphin/Trident between two dolphins

[Christopher H2]

2.10 grams
14 mm diameter

Obverse has an animal standing /walking left on a line. The head is a bit off-flan but I think I see the goatee and horns of a goat.
Coin-in-hand, two or three letters are visible above. Looks like the first one is a B.

The reverse seems to have a + with a small o in one of the angles, so my best guess is that it's a four-spoked wheel with Greek letters in the angles. It's definitely parted into four segments.

If I'm wrong about the goat, then this coin really looks like those cow-standing-left-on-dolphin / incuse windmill sail pattern coins from Byzantium, except it's clearly copper.

Maybe it's an old fourrée with all the silver gone?

Two images of obv, one with 5% extra brightness and contrast

Four images of rev, same pic rotated 90, 180 and 270 degrees.

[Christopher H2]

Aha, finally nailed this one!

Thank you FORVM for, amongst many things, being an awesomely searchable database of information!

https://www.forumancientcoins.com/catalog/roman-and-greek-coins.asp?param=00785z00.jpg&vpar=581&zpg=618&fld=https://www.forumancientcoins.com/Coins/

"Bronze AE 15, SNG BM 49 - 50, SGCV I 1591, aF, Byzantion (Istanbul, Turkey) mint, weight 3.7g, maximum diameter 15.2mm, die axis 0o, Mid 4th - 3rd century B.C.; obverse cow standing left on dolphin left, BY above (the first letter is an archaic form of "B" used at Byzantium); reverse trident between two dolphins;"

I even read the B correctly in my first post and noticed that it looked like the Byzantion issues. I'm getting better at this!