Wikipedia
Tlaltecuhtli is a pre-Columbian Mesoamerican deity, identified from sculpture and iconography dating to the Late Postclassic period of Mesoamerican chronology (ca. 1200–1519), primarily among the Mexica (Aztec) and other Nahuatl-speaking cultures. Tlaltecuhtli is also known from several post-conquest manuscripts that surveyed Mexica mythology and belief systems, such as the Histoyre du méchique compiled in the mid-16th century.
According to Alfonso Caso There were four earth gods - Tlaltecuhtli who was male and three earth goddesses - Coatlique, Cihuacoatl and Tlazolteotl. In one of the Mexica creation accounts Tlaltecuhtli is described as a sea monster who dwelled in the ocean after the fourth Great Flood, an embodiment of the raging chaos before creation. Quetzalcoatl and Tezcatlipoca, in the form of serpents, tore him in half, throwing half upwards to create the sky and stars and leaving the other half to become the land of the earth. He remained alive, however, and demanded human blood.
Although the deity's name is masculine in Nahuatl, some modern scholars, notably Miller and Taube interpret some representations of Tlaltecuhtli as exhibiting female characteristics, particularly his typical pose which they interpret as the characteristic position of a woman giving birth. According to Miller and Taube p. 167: "Tlaltecuhtli literally means "earth Lord," but most Aztec representations clearly depict this creature as female, and despite the male gender of the name, some sources call Tlaltecuhtli a goddess. Usually in a hocker, or birth-giving squat, with head flung backwards and her mouth of flint blades open..." Miller and Taube provide an extensive bibliography but use no footnotes so it's impossible to know what sources identify Tlaltecuhtli as a female figure. They identify their main source for Aztec mythology as the Florentine codex however Book 1 of the codex, the Gods, does not include this god. Since Miller and Taube does not refer to primary or secondary sources, one must consider the fact that their identification of Tlaltecuhtli as female is their interpretation of the iconography. Other scholars think that this pose is him crouching under the earth, mouth open, waiting to devour the dead.
According to Alfonso Caso, in the Bodley Codex he was born in a flaming tree Caso. p. 25-26: I-III who is "Sun Ornament", but later his child is called Tlaltecutli (Earth Lord.) He became an Earth Lord when according to Miller and Taube, he was torn apart and his parts were taken to Earth.
Recently a monolith of the deity was unearthed in Mexico City.