Johann Baptist Ritter von Spix (1781-1826), a German zoologist, was famous in his time and highly honored after making one of the first exploration voyages in the wildest part of Brazil. He was almost forgotten in the annals of history for nearly two centuries after his birth, at which time some enlightened biographers brought him back into prominence in both the biological and zoological fields. On the contrary though, he had never been forgotten in the science of odontostomatology thanks to his discovery of the "Lingula Mandibularis" also known as "Spine of Spix". Johannes Baptist Spix was born in Hoechstadt, Germany in 1781. He was the Conservator of the Museum of Natural History in Munich and was a distinguished Comparative Anatomist. He died Munich inl 1826. The purposes of this work are to present some biographical notes on J.B. Ritter von Spix, to explain whythe "Lingula Mandibularis" has been called by the name of Spix and why this eponym has been used as such.