Wich was the first thing developed? Thought or languaje?

Saying it in first instance, we all may say that obviously is thought. BUT, if you analyze it, languaje is an expression of our thoughts, and our thoughts are an expression of what we hear and interactuate with.

There has been different hypothesis, like these ones:
"The Language of Thought Hypothesis" of Aydede, Murat, from Stanford Encyclopedia of Philosophy, best known as "LOTH" postulates that thought take place in a mental language. Of this statement I understand that that, to make thought we requiere this mental language that there says, so that means that in this Hypotesis, Language go first, because without language, we don´t have thougths, and language allow to have thoughts.

Ferdinand de Saussure, a Swiss linguist whose ideas laid the foundation for many discoveries before, in what linguistics is. Saussure postulates that language is linked with thoughts, and you can´t separate them. Also incorporated new terms: Langue and Parole. Langue refers to the abstract system of signs and rules that make up the structure and nature of language. And parole is the realization of language in practice, the words, phrases and sentences as they are actually used.

My own theory is that thoughts came first, because, languaje itself, is to communicate your thoughts to others, you HAVE to think to speak, but you dont have to speak to think. In that case, recently born babies won't think, nor rabbits, nor any other animal that doesnt emmit sounds.