From the introduction: "The purpose of this paper is to present some results of research on Guajajara (G), a Tupi-Guarani language of Northeast Brazil, with the hope of contributing some facts of interest to universal grammarians.
"Guajajara is unique in that due to its particular combination of morphological and syntactic traits, it is inconsistent in terms of commonly discussed typological parameters.
"Some features of interest are: 1. Double cross-referencing of core NPs. a. General accusativity in cross-referencing pronominal clitics attached to the end of the clauses. b. Mixed ergativity with accusativity in the cross-referencing pronominal verb prefixes.
2. Registration in the verb of topicalization of oblique nominals.
3. The division of clauses into spans for the purposes of placement of tense, and other clitics, with no regard for the particular syntactic relation that the material of a span has to the clause as a whole.
4. The ergativity-accusativity splits, none of which are unique in themselves, but whose combination in G may be unique. Those splits are on the basis of independency-dependency of the verb, volitionality of the subject, on whether or not the subject of the dependent intransitive verb is the same as the subject of the independent verb, volitionality of the subject, and whether or not the subject of the dependent intransitive verb is the same as the subject of the independent verb, and on whether or not the verb in the sentence is preceded by an oblique nominal such as locative, or by an adverb. A split also may be conditioned on the relationship of object to subject on the agency hierarchy."
Harrison, Carl H.
"Typological disharmony and ergativity in Guajajara,"
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 27, Article 6.
Available at: https://commons.und.edu/sil-work-papers/vol27/iss1/6