Autapomorphies of Parecbasis cyclolepis:
1. Length of supraoccipital spine (53): (1> 0) extends posteriorly to, at least, middle length of neural complex of Weberian apparatus. Paralleled in node 207 and in Odontostilbe paraguayensis .
2. Lateral coverage of dilator fossa by sixth infraorbital (69): (1> 0) almost complete, at least in its ventral border. Reversal of synapomorphy 2 of node 197. Paralleled in node 232.
3. Dorsal end of laterosensory canal of preopercle and suprapreopercle (82): (0> 1) overlapping anterodorsal process of opercle. Paralleled in the Alestidae, in node 230, and in Bario steindachneri, Hyphessobrycon eques, Pristella maxillaris, and Stichonodon insignis .
4. Lateral ridge of anguloarticular (107): (0> 1) present. Paralleled in the Cheirodontinae, in node 191, and in Aphyocharacidium bolivianum .
5. Maxillary teeth (134): (1> 0) absent. Paralleled in Aulixidens eugeniae, Coptobrycon bilineatus, Iguanodectes geisleri, and Stichonodon insignis . Some trees: Paralleled in Hyphessobrycon elachys and Psellogrammus kennedyi .
6. Relative length of palatine (172): (1> 0) approximately onehalf length of ectopterygoid, or less. Reversal of synapomorphy 4 of node 197. Paralleled in node 255 and in Acrobrycon tarijae, Aphyocharax nattereri, Gymnocharacinus bergii, and Piabina argentea .
7. Rows of gill rakers on first ceratobranchial (192): (0> 1) two. Reversal of synapomorphy 3 of node 179. Paralleled in the Iguanodectinae, in node 280, and in Brycon orbignyanus, Bryconaethiops macrops, Carlana eigenmanni, Cheirodon interruptus, Hoplocharax goethei, Hyphessobrycon elachys, Odontostilbe microcephala, Prodontocharax melanotus, and Rhaphiodon vulpinus . Some trees: Paralleled in node 249 and in Attonitus ephimeros .
8. Number of gill rakers on first hypobranchial and ceratobranchial (195): (1> 0) 16 or more. Paralleled in nodes 177 and 183 and in Astyanax latens, A. cf. rutilus, A. pelegrini, Hoplias cf. malabaricus, Hyphessobrycon socolofi, Moenkhausia dichroura, Piaractus mesopotamicus, and Stichonodon insignis .
9. Laminar bony ridge on dorsal margin of abdominal ribs (224): (0> 1) present.Paralleled in node 297 and in Stichonodon insignis .
10. Transitional vertebrae with haemal canal (229): (1> 0) present. Reversal of synapomorphy 6 of node 195. Paralleled in Serrapinnus calliurus .
11. Relative position of dorsal-fin anterior insertion (265): (1> 0) anterior to or at vertical through pelvic-fin origin. Paralleled in node 282 and in Creagrutus anary, Exodon paradoxus, and Moenkhausia xinguensis .
12. Bony lamellae associated with supraneurals (282): (0> 1) wider than primary axis of supraneurals.Reversal of synapomorphy 5 of node 197. Paralleled in Prodontocharax melanotus .
Some trees:
13. Number of maxillary teeth (135): (1> 0) only one, or absent. (k9-12). Paralleled in the Astyanax clade, in nodes 284 and 290, and in Aulixidens eugeniae, Cheirodon interruptus, Coptobrycon bilineatus, Hyphessobrycon bifasciatus, and Iguanodectes geisleri . Some trees: Paralleled in Hasemania nana and Paracheirodon axelrodi .
14. Development of transverse process of neural arch of third vertebra (219): (0> 1) well developed and extending beyond anterior margin of tripus. (k13-14). Paralleled in node 302, and in Agoniates anchovia, Cyanocharax alburnus, Deuterodon langei, Engraulisoma taeniatum, Hemiodus cf. thayeria, Roeboexodon geryi, and Thayeria obliqua. Some trees: Paralleled in Microschemobrycon casiquiare .