In progressive P. hemioliopterus this new related main section of the skull roof is nearly totally ornamented by reticulating ridges and you may pits, having couple if any elongate, parallel ridges and you will sulci ( Fig. 4a). About Acre Phractocephalus the new main section of the skull rooftop has many elongate ridges and sulci along with reticulating ridges and you will pits.
The brand new horizontal ethmoid bones from P
2) Mesethmoid bone very broad ( Dining table 1); dorsal epidermis generally ornamented; prior edge hardly emarginate so you’re able to lightly game ( Fig. 3a).
Brand new mesethmoid limbs from P. hemioliopterus is fairly narrow-necked, smaller widely ornamented just centrally and posteriorly, and its prior border is emarginate otherwise shallowly concave ( Fig. 4a). nassi.
3) Lateral ethmoid perhaps not excessively projecting anteriorly more palatine condyle; the lateral margin convex and you will getting rid of orbital notch into the margin from head rooftop ( Fig. 3a).
hemioliopterus is also not continuously projecting anteriorly over the olfactory region or palatine condyle; but it is concave laterally, and has a well defined orbital sulcus on margin off skull rooftop ( Fig. 4a). Regarding Acre Phractocephalus the latest horizontal ethmoid methods much anteriorly more the latest olfactory region and palatine condyle; it’s convex sideways, eliminating the fresh orbital sulcus toward margin of head roof.
Modern P. hemioliopterus keeps an unbarred prior cranial fontanelle within this a prominent despair out-of epiphyseal area ( Fig. 4a), whereas from the Acre Phractocephalus the fresh new fontanelle and anxiety of your epiphyseal area lack.
5) Supraoccipital techniques having rounded lateral and you can posterolateral margins, posterior margin concave medially; supraoccipital processes much time, in dorsal have a look at completely covering modified prior spinal vertebrae away from Weberian complex ( Fig. 3a).
The fresh opercle P
Into the progressive P. hemioliopterus the fresh supraoccipital process are brief, into the dorsal examine maybe not totally coating altered vertebrae out of Weberian state-of-the-art; it has angular lateral and you may posterolateral margins, and its particular posterior margin try unpredictable in order to concave medially and you may bearing an intense unornamented expansion lower than prior nuchal plate ( Fig. 4a). On Acre Phractocephalus the new supraoccipital procedure are enough time, totally within the Weberian state-of-the-art; its procedure enjoys angular edges and you may straight horizontal margins, and its posterior ented expansion less than prior nuchal dish.
hemioliopterus is incompletely wrapped in reticulating ridges and you can pits ( Fig. 5c). Brand new opercle is actually up to now not familiar regarding Acre Phractocephalus.
7) Cleithrum which have rough ornamentation extending with each other ventral boundary developing outward fat otherwise «shoulder» horizontal in order to back articulation; fat away from «shoulder» terminating posteriorly, according to termination out-of articular retailer out of pectoral spine ( Figs. 5e-g).
The brand new cleithrum out of P. hemioliopterus does not have coarse ornamentation together ventral edge of «neck,» additionally the lateral fat out of «shoulder» terminates rear to the point out-of articular retailer off pectoral spine ( Figs. 5i, j). Zero cleithrum of Acre Phractocephalus is known.
8) Pectoral lower back ornamentation reigned over by coarse subparallel ridges and sulci, and you will seemingly partners reticulating ridges and you may pits ( Fig. 5h).
The fresh new pectoral spine ornamentation of P. hemioliopterus escort in Santa Clara try reigned over from the reticulating ridges and you can pits ( Fig. 5i). The pectoral lower back of the Acre Phractocephalus is actually but really not familiar.
Etymology. New Urumaco types of Phractocephalus is known as getting Dr. Pedro Nass inside detection off his benefits on the systematics and morphology from pimelodid catfishes regarding South america.
Malfunction. Get a hold of Lundberg mais aussi al. (1988) having malfunction out-of neurocranium (MCN.USB 72-85 PB) and additional proportions. Next info is available with the newest holotype and you will recently received specimens.
Neurocranium, dorsal element ( Fig. 3a). Definition particular head around square, depth round the lateral ethmoids equivalent to thickness around the sphenotics, that widths somewhat below restriction width all over pterotic wings; thickness all over pterotics consisted of 2.twenty-five moments in the (45% of) dorsal skull length out of mesethmoid tip to help you posterior edge of supraoccipital process. Surface mainly flat however, margins rounded slightly down and you may dorsal midline all the more arched posteriorly. Most of the skeleton ornamented having rough reticulating ridges and round pits and some longitudinally elongate ridges and you can grooves, except for olfactory products and you may extremities out-of mesethmoid cornua.
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