Not officially, BUT Benjamin Huffman, who is an incredible designer on DMs Guild (*cough cough* pugilist class is the best unofficial class out there *cough cough*) made the Dragontortleborn which is pretty fun!
Its not quite what you are after but I made a character for a one shot called "Captain Squall the Dargon Tortle" (Tortle race + Draconic Socerer w/ Dragon Turtle ancestor) link to character sheet here if you want to have a peek.
This is a thread for anyone to ask weird D&D questions that they don't really need answers to, but they still want to know.
I don't believe there IS... but homebrew is now calling my name.
There is not an official Dragon Turtle Dragonborn.
Please check out my homebrew, I would appreciate feedback:
Spells, Monsters, Subclasses, Races, Arcknight Class, Occultist Class, World, Enigmatic Esoterica forms
Dragon Turtles don't have a Dragonborn broodlings...yet.
"Sooner or later, your Players are going to smash your railroad into a sandbox."
-Vedexent
"real life is a super high CR."
-OboeLauren
"............anybody got any potatoes? We could drop a potato in each hole an' see which ones get viciously mauled by horrible monsters?"
-Ilyara Thundertale
Not officially, BUT Benjamin Huffman, who is an incredible designer on DMs Guild (*cough cough* pugilist class is the best unofficial class out there *cough cough*) made the Dragontortleborn which is pretty fun!
Its not quite what you are after but I made a character for a one shot called "Captain Squall the Dargon Tortle" (Tortle race + Draconic Socerer w/ Dragon Turtle ancestor) link to character sheet here if you want to have a peek.
https://drive.google.com/open?id=115iiwxzNWxwH-7rGLv-xkHiKpUjcUPS7
That's cool!