Symphysis Of Lower Jaw Research Articles

Acropoma musorstom, a new lanternbelly (Acropomatidae) from the South Pacific and the first record of Acropoma splendens from the Andaman Sea off southwestern Thailand

A new species of the genus Acropoma, A. musorstom sp. nov. is described based on four specimens (126.3–143.0 mm in standard length: SL) collected from Vanuatu and the Molucca Islands, Indonesia. The present species is distinguished from other congeners by a combination of the following characters: luminous gland short, U-shaped around anus; luminous-gland length 10.3–13.7% SL; symphysis of lower jaw not protruded; proximal radial of first anal-fin pterygiophore with concavity on anterior surface; anus situated closer to pelvic-fin insertion than to origin of anal fin; weakly ctenoid scales on lateral side of body; vertical line on cheek absent; scales between first dorsal-fin base and lateral line 4; pectoral-fin rays 16–17; and gill rakers 20–21. Acropoma splendens (Lloyd 1909) collected from off Phuket, it represents the first record of this species from the Andaman Sea off southwestern Thailand. A key to the species of Acropoma currently known from the Indo-Pacific is provided.

Description of a new species of the genus Acropoma (Acropomatidae) from the Arafura Sea with a redescription of Acropoma leobergi Prokofiev 2018 and the first record of Acropoma boholensis Yamanoue and Matsuura 2002 from the South China Sea

A new species of the genus Acropoma, A. arafurensis sp. nov., is described based on two specimens (57.3–76.2 mm standard length: SL) collected from the Arafura Sea. The present species is distinguished from other congeners by a combination of the following characters: luminous gland U-shaped extending from throat to posterior tip of pectoral fin; luminous-gland length 29.5–32.0% SL; symphysis of lower jaw not sharply protruded; proximal radial of first anal-fin pterygiophore with concavity on anterior surface; anus situated closer to pelvic-fin insertion than to origin of anal fin; cycloid scales on lateral side of posterior half of body; vertical line on cheek absent; scales between first dorsal-fin base and lateral line 4; pectoral-fin rays 15; and gill rakers 20–21. Acropoma leobergi is redescribed based on 60 specimens (38.6–143.5 mm SL) from Taiwan, Philippines, and northern and west coast of Australia. Additionally, two specimens (94.9–103.1 mm SL) of A. boholensis collected from Luzon, Philippines, represent the first record of this species from the South China Sea.

A review of the deepwater cardinalfish genus Epigonus (Perciformes: Epigonidae) of the Western Indian Ocean, with description of two new species.

The fishes of the genus Epigonus Rafinesque, 1810 in the Western Indian Ocean (including the Red Sea and the Gulf of Aden) are reviewed. Twelve species of the genus are recognized: Epigonus angustifrons Abramov Manilo, 1987; E. denticulatus Dieuzeide, 1950; E. elongatus Parin Abramov, 1986; E. exodon Okamoto Motomura, 2012; E. lenimen (Whitley, 1935); E. macrops (Brauer, 1906); E. marimonticolus Parin Abramov, 1986; E. marisrubri Krupp, Zajonz Khalaf, 2009; E. pectinifer Mayer, 1974; E. robustus (Barnard, 1927); E. telescopus (Risso, 1810); E. waltersensis Parin Abramov, 1986, and two new species, E. bispinosus n. sp. and E. idai n. sp. Epigonus bispinosus and E. idai belong to the E. constanciae group, defined as having a pungent opercular spine, more than 45 pored lateral-line scales, and lacking an isolated dorsal fin spine between the first- and second dorsal fins. Epigonus bispinosus differs from other members of the group in having two small spines on the symphysis of lower jaw, a pair of ribs on the last abdominal vertebra, 10 + 15 vertebrae, 31-33 gill rakers and lacking a maxillary mustache-like process. Epigonus idai differs from other members of the group in having a pair of ribs on the last abdominal vertebra, 4-5 tiny projections present on symphysis of lower jaw, 10 + 15 vertebrae, strongly ctenoid scales, and 28-29 gill rakers, and in lacking a maxillary mustache-like process. A key to the species, photographs, diagnoses, and distributions in the Western Indian Ocean are given.

Three new species of the genus Acropoma (Perciformes: Acropomatidae) from the Indian Ocean

Three new species of Acropoma are described from the Indian Ocean. These species have been identified as “A. japonicum Gunther 1859” by many authors, but clearly differ from A. japonicum in the shape and length of the luminous gland, counts of pectoral-fin rays and scales between first dorsal-fin base and lateral line, and other diagnostic characters. Acropoma heemstrai sp. nov. is described on the basis of 17 specimens (53.1–121.0 mm standard length: SL) collected from South Africa and Mozambique. It is distinguished from other congeners by its unique moderate Y-shaped luminous gland, extending from the throat to midway between the origins of the pelvic and anal fins, (luminous gland length 23.1–27.0% SL) and a pointed protrusion on the symphysis of lower jaw. Acropoma lacrima sp. nov. is described on the basis of 6 specimens (64.1–77.9 mm SL) collected from the Arabian Sea. Also, this species has been previously reported as “A. argentistigma Okamoto and Ida 2002” from the Bay of Bengal. It is characterized by having a vertical line on the cheek, short U-shaped luminous gland (luminous gland length 15.0–16.0% SL), and weakly ctenoid and cycloid scales on the side of the body. Acropoma neglectum sp. nov. is described on the basis of 5 specimens (105.3–168.5 mm standard length: SL) collected from the Gulf of Aqaba, northern Red Sea. It is similar to A. japonicum in having a short U-shaped luminous gland, but differs in having a shorter luminous gland (12.0–13.4% SL vs. 17.0–20.8% SL in A. japonicum), 3 scales between first dorsal-fin base and lateral line (vs. 4 scales in A. japonicum), and 16–17 pectoral-fin rays [vs. 14–16 (modally 15) in A. japonicum].

Two new species of deepwater cardinalfish from the Indo-Pacific, with a definition of the Epigonus pandionis group (Perciformes: Epigonidae)

Two new Indo-Pacific species of deepwater cardinalfish, Epigonus lifouensis and E. tuberculatus are described based on the specimens collected from the Loyalty Islands and Cocos-Keeling Islands, respectively. These species belong to the Epigonus pandionis group defined as lacking an opercular spine, having more than 43 pored lateral-line scales to the end of the hypural and dorsal-fin rays VII-I, 9–11. Epigonus lifouensis is distinguished from other members of the group by a combination of the following characters: ribs present on the last abdominal vertebra; tongue toothless; tubercle absent on inner symphysis of lower jaw; eye elliptical; total gill rakers 24–25; pectoral-fin rays 18–19; pyloric caeca 10–13; body depth 17.0–17.1 % SL; and posterior half of oral cavity and tongue black. Epigonus tuberculatus is distinguished from other members of the group by a combination of the following characters: ribs on the last abdominal vertebra reduced or absent; tongue toothless; tubercle present on inner symphysis of lower jaw; total gill rakers 21–22; pectoral-fin rays 19–20; pyloric caeca 8–10; orbital diameter 14.5–15.4 % SL; and lower-jaw length 16.0–17.6 % SL. A key to the species and some comments on the group are provided based on examination of all members (nine species, including two new species) of the group.

Two new species of the genus Epigonus (Perciformes: Epigonidae) from the South Pacific, with a definition of the Epigonus constanciae group

Two new species of Epigonus are described from the South Pacific. Epigonus chilensis is described on the basis of five specimens (166.3–208.3 mm standard length) collected from off Chile. It closely resembles Epigonus lenimen (Whitley 1935), but differs in the presence of a minute tubercle on symphysis of lower jaw, body depth, orbital diameter, and lower-jaw length. Epigonus machaera is described on the basis of eight specimens (157.2–174.3 mm standard length) collected from the Chatham Rise, east of New Zealand. It closely resembles Epigonus robustus (Barnard 1927), but differs in the shapes of tongue and two nub-like structures on symphysis of lower jaw and second dorsal-fin spine length. Besides the two new species, 14 species of the genus are characterized by having a pungent opercular spine, more than 40 pored lateral-line scales to end of hypural, and dorsal-fin rays VII-I, 8–10. These species belong to the Epigonus constanciae group, defined in this study. A key to the species in the group is provided.

Histological evaluation of bone response to pediatric endodontic pastes: an experimental study in guinea pig

This study aimed to evaluate by the intra-osseous implant technique the most commonly used materials for pulp therapy in pediatric dentistry: calcium hydroxide (CH), Guedes Pinto paste and CTZ paste, according to FDI (1980) and ANSI/ADA (1982) recommendations. Thirty guinea pigs, 10 for each material, divided into experimental periods of 4 and 12 weeks received one implant on each side of the lower jaw symphysis. The external lateral tube wall served as control for the technique. At the end of the observation periods, the animals were euthanized and specimens were prepared for routine histological examination. It was observed that CH and CTZ paste induced severe inflammation, a large amount of necrotic tissue, lymphocytes, foreign body cells and bone resorption, while Guedes Pinto Paste induced little or no inflammation in the 4-week observation period. After 12 weeks, the reactions to CH and Guedes Pinto paste were also absent/mild, presenting a general pattern of replacement by recently formed bone tissue while a moderate to severe inflammatory response was observed with CTZ paste. Guedes Pinto paste presented acceptable biocompatibility levels in both analyzed periods; CH only showed acceptable biocompatibility in the 12-week period while CTZ paste showed no biocompatibility in both periods. Among the tested materials, only Guedes Pinto paste presented an acceptable biocompatibility.

Pseudobunocephalus, a new genus of banjo catfish with the description of a new species from the Orinoco River system of Colombia and Venezuela (Siluriformes: Aspredinidae)

Pseudobunocephalus, a new genus of small banjo catfishes (< 80 mm SL), is distinguished from all other aspredinid genera by the following unique features: mandibular teeth restricted to a patch near symphysis of lower jaw; no contact between the metapterygoid and quadrate; autopalatine posteriorly forked with two separate cartilages; absence of the fourth pharyngobranchial; absence of gill rakers on all branchial arches; and lack of bifid hemal spines on vertebrae that articulate with anal-fin pterygiophores. As defined Pseudobunocephalus contain a new species, P. lundbergi from the Orinoco River basin, along with five other species previously assigned to the genus Bunocephalus: P. amazonicus, P. bifidus, P. iheringii, P. quadriradiatus, and P. rugosus.

Pelagic juvenile of Halargyreus johnsonii (Gadiformes: Moridae) from Suruga Bay, Japan

A pelagic juvenile (43.0 mm standard length) of the deep-sea gadiform fish Halargyreus johnsonii was collected by a larva net towed at depths from 200 m to 90 m at Suruga Bay, Japan. The specimen had an elongate body, eyes located dorsally on the head, a depressed anal fin, small bony tubercles on the lower jaw symphysis, elongate pelvic fin rays, and a pointed caudal fin. The body was silver with numerous small black spots. The gut was filled with a copepod, Pareuchaeta russelli, that is characterized by a surface to mesopelagic distribution.

A new baphetid (stem tetrapod) from the Upper Carboniferous of Tyne and Wear, U.K., and the evolution of the tetrapod occiput

A new genus and species of baphetid, Kyrinion martilli, is described from the Westphalian A (Upper Carboniferous) of Tyne and Wear, England. The skull, braincase, and partial lower jaws are preserved in a nodule of iron-rich seat-earth, in an almost uncrushed state. The occiput and both stapes are in place. The palate and braincase are united by a continuous sheet of denticulated pterygoid and parasphenoid eliminating the interpterygoid vacuities completely, and the parasphenoid bounds deep parasphenoidal tubera; the marginal palatal bones, pterygoid, and dentary are united by interdigitated sutures, rendering the whole skull akinetic. The orbits are approximately triangular, without the "pinching in" that defines an antorbital embayment in other baphetids. The maxilla has a very narrow exposure beneath and posterior to the orbit, and though it and the lacrimal lack lateral line grooves, there is a short stretch on the quadratojugal. Unlike Megalocephalus, the lower jaw symphysis is relatively simple and does not bear a "brassicate" structure and the parasymphysial plate lacks teeth. The stapes is broad and flat distally, with its distal end lying against the palatal bones as in other early tetrapods, but it is difficult to envisage a structural role for this element as suggested by recent hypotheses. The basi- and exoccipitals co-ossified as in some specimens of Greererpeton and Acanthostega, but unlike the latter, the condyle is almost fully ossified. The exoccipitals do not contact the skull roof as they do in temnospondyls, but fully ossified paroccipital processes suture with the tabulars, a feature suggested as synapomorphous for baphetids plus temnospondyls. The specimen also preserves a rib, possibly but not certainly cervical, and an atlas arch. The proatlantes of Loxomma are descibed and figured.

The status ofAnarosaurus multidentatus von Huene (Reptilia, Sauropterygia), from the lower anisian of the lechtaler alps (Arlberg, Austria)

The holotype ofAnarosaurus multidentatus von Huene (1958) from the lowermost Anisian of the Austrian Alps is redescribed and referred to the genusCymatosaurus. Eusauropterygian characters shared byA. multidentatus are the elongated and broadened Symphysis, and the contours of the lower jaw suggesting the presence of a constricted snout. Morphological details of the lower jaw Symphysis showA. multidentatus to be close toCymatosaurus among stem-group sauropterygians.Cymatosaurus multidentatus is the only representative of its genus known so far from the Alpine Triassic, and it represents the earliest known sauropterygian from the Alpine Triassic.