TABLE 1. Comparison of different species of Mourasuchus. Characters 1-8 are taken from the emended diagnosis of M. nativus of Bona et al. (2013a, b); characters 9 and 10 from Bocquentin Villanueva (1984). Data on M. amazonensis is based on holotype DGM 526-R as described and shown by Price (1964) and Langston (1966). Data on M. nativus is based on holotype MLP 73-IV-15-8 and specimen MLP 73-IV-15-9 as shown by Bona et al. (2013a, b), as well as on specimen UFAC- 1424 in Tineo et al. (2015). Data on M. atopus is based on holotype UCMP 38012 in Langston (1965, 1966). Data on M. arendsi is based mainly on holotype UNEFM-CIAAP-1297 as described by Bocquentin Villanueva (1984) 1, as well as on our revised interpretation of the holotype presented herein2. As noted in the discussion, some characters are deemed to be of little taxonomic utility (e.g., characters 9, 10) and need to be treated with caution.


M. amazonensis (holotype)

M. atopus (holotype)

M. nativus (holotype)

UFAC-1424 (referred to M. nativus)

M. arendsi (holotype)



1. prominent squamosal horns absent ? present present absent1,
? present
2. marked knobs or bosses at orbital margin present present ? absent present present present
3. supratemporal fenestra surrounded rostrally by postorbital and parietal absent absent present present present ? present
4. dentary linear between 4th and 10th alveoli present present ? present present present (but obscured) ?
5. orbits smaller than infratemporal fenestrae present present ? present present present present
6. middle crest on posterior dorsal surface of parietal absent absent present present absent 1, present 2 ? present
7. pronounced notch at lateral edge of jugals present absent ? present absent 1, present 2 present ?
8. lateral border of maxillae extend parallel to each other absent present ? absent absent absent ?
9. premaxillary perforations 2


(1 st and 4 th)



(1 st and 4 th)

? 4? 4


(1 st -4 th)



right: 3


(1 st -3 rd)


left: 3


(2 nd -4 th)

10. palatine constriction weak? strong ? weak weak 1 weak? (area damaged) ?