scholarly journals The ontogenetic transformation of the mesosaurid tarsus: a contribution to the origin of the primitive amniotic astragalus

2016 ◽  
Author(s):  
Graciela Piñeiro ◽  
Pablo Núñez Demarco ◽  
Melitta D Meneghel
Keyword(s):  
The Other ◽  
Ossification Center ◽  
Advanced Stage ◽  
Late Permian ◽  
Early Permian ◽  
Stage Of Development ◽  
Tarsal Bones ◽  
Single Bone ◽  
Transformation Series

The hypotheses about the origin of the primitive amniotic tarsus are very speculative. Early studies argued that the origin of the astragalus, one of the largest proximal bones in the tarsus of basal amniotes, was produced by either the fusion of two, three, or even four of the original tarsal bones, the intermedium, the tibiale and the proximal centralia (c4 and c3), or that the intermedium alone transforms into the primitive astragalus. More recent studies have shown that the structure of the tarsus in Captorhinus supports the former hypothesis about a fusion of the intermedium, the tibiale, the proximal centrale (c4) and eventually c3, producing a purportedly multipartite structure of the amniotic astragalus, but the issue remained contentious. Very well preserved tarsi of the Early Permian aquatic amniote Mesosaurus tenuidens Gervais, 1864-1865, which represent the most complete ontogenetic succession known for a basal amniote (the other exceptional one is provided by the Late Permian diapsid Hovasaurus boulei Piveteau, 1926), suggest that there is more than one ossification center for the astragalus and that these fuse during late embryonic stages or maybe early after birth. A non-hatched Mesosaurus in an advanced stage of development shows that the tarsus is represented by a single bone, most probably the astragalus, which seems to be formed by the suturing of three bones, which we interpret as being the intermedium, the tibiale, which could have already integrated the c4 in an earlier stage of the development, and the c3. An amniote-like tarsal structure is observed in very basal Carboniferous and Permian tetrapods such as Proterogyrinus, Gephyrostegus, the diadectids Diadectes and Orobates, some microsaurs like Tuditanus and Pantylus, and possibly Westlothiana, taxa that were all considered as true amniotes in their original descriptions. Therefore, the structure of the amniotic tarsus, including the configuration of the proximal series formed by the astragalus and the calcaneum, typically a pair of enlarged bones, could have been established well before the first recognized amniote walked on Earth. Accordingly, the tarsus of these taxa does not constitute specialized convergences that appeared in unrelated groups, they might be instead, part of a transformation series that involves taxa closely related to the early amniotes as some hypotheses have suggested.

scholarly journals The ontogenetic transformation of the mesosaurid tarsus: a contribution to the origin of the primitive amniotic astragalus

2016 ◽  
Author(s):  
Graciela Piñeiro ◽  
Pablo Núñez Demarco ◽  
Melitta D Meneghel
Keyword(s):  
The Other ◽  
Ossification Center ◽  
Advanced Stage ◽  
Late Permian ◽  
Early Permian ◽  
Stage Of Development ◽  
Tarsal Bones ◽  
Single Bone ◽  
Transformation Series

The hypotheses about the origin of the primitive amniotic tarsus are very speculative. Early studies argued that the origin of the astragalus, one of the largest proximal bones in the tarsus of basal amniotes, was produced by either the fusion of two, three, or even four of the original tarsal bones, the intermedium, the tibiale and the proximal centralia (c4 and c3), or that the intermedium alone transforms into the primitive astragalus. More recent studies have shown that the structure of the tarsus in Captorhinus supports the former hypothesis about a fusion of the intermedium, the tibiale, the proximal centrale (c4) and eventually c3, producing a purportedly multipartite structure of the amniotic astragalus, but the issue remained contentious. Very well preserved tarsi of the Early Permian aquatic amniote Mesosaurus tenuidens Gervais, 1864-1865, which represent the most complete ontogenetic succession known for a basal amniote (the other exceptional one is provided by the Late Permian diapsid Hovasaurus boulei Piveteau, 1926), suggest that there is more than one ossification center for the astragalus and that these fuse during late embryonic stages or maybe early after birth. A non-hatched Mesosaurus in an advanced stage of development shows that the tarsus is represented by a single bone, most probably the astragalus, which seems to be formed by the suturing of three bones, which we interpret as being the intermedium, the tibiale, which could have already integrated the c4 in an earlier stage of the development, and the c3. An amniote-like tarsal structure is observed in very basal Carboniferous and Permian tetrapods such as Proterogyrinus, Gephyrostegus, the diadectids Diadectes and Orobates, some microsaurs like Tuditanus and Pantylus, and possibly Westlothiana, taxa that were all considered as true amniotes in their original descriptions. Therefore, the structure of the amniotic tarsus, including the configuration of the proximal series formed by the astragalus and the calcaneum, typically a pair of enlarged bones, could have been established well before the first recognized amniote walked on Earth. Accordingly, the tarsus of these taxa does not constitute specialized convergences that appeared in unrelated groups, they might be instead, part of a transformation series that involves taxa closely related to the early amniotes as some hypotheses have suggested.

scholarly journals The ontogenetic transformation of the mesosaurid tarsus: a contribution to the origin of the primitive amniotic astragalus

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2036 ◽  
Author(s):  
Graciela Piñeiro ◽  
Pablo Núñez Demarco ◽  
Melitta D. Meneghel
Keyword(s):  
The Other ◽  
Ossification Center ◽  
Advanced Stage ◽  
Late Permian ◽  
Early Permian ◽  
Stage Of Development ◽  
Tarsal Bones ◽  
Single Bone ◽  
Transformation Series

The hypotheses about the origin of the primitive amniotic tarsus are very speculative. Early studies argued that the origin of the astragalus, one of the largest proximal bones in the tarsus of basal amniotes, was produced by either the fusion of two, three, or even four of the original tarsal bones, the intermedium, the tibiale and the proximal centralia (c4 and c3), or that the intermedium alone transforms into the primitive astragalus. More recent studies have shown that the structure of the tarsus inCaptorhinussupports the former hypothesis about a fusion of the intermedium, the tibiale, the proximal centrale (c4) and eventually c3, producing a purportedly multipartite structure of the amniotic astragalus, but the issue remained contentious. Very well preserved tarsi of the Early Permian aquatic amnioteMesosaurus tenuidensGervais, 1864–1865, which represent the most complete ontogenetic succession known for a basal amniote (the other exceptional one is provided by the Late Permian diapsidHovasaurus bouleiPiveteau, 1926), suggest that there is more than one ossification center for the astragalus and that these fuse during late embryonic stages or maybe early after birth. A non-hatchedMesosaurusin an advanced stage of development shows that the tarsus is represented by a single bone, most probably the astragalus, which seems to be formed by the suturing of three bones, here interpreted as being the intermedium, the tibiale, probably already integrated to the c4 in an earlier stage of the development, and the c3. An amniote-like tarsal structure is observed in very basal Carboniferous and Permian tetrapods such asProterogyrinus, Gephyrostegus, the diadectidsDiadectesandOrobates, some microsaurs likeTuditanusandPantylusand possiblyWestlothiana, taxa that were all considered as true amniotes in their original descriptions. Therefore, the structure of the amniotic tarsus, including the configuration of the proximal series formed by the astragalus and the calcaneum, typically a pair of enlarged bones, could have been established well before the first recognized amniote walked on Earth. Accordingly, the tarsus of these taxa does not constitute specialized convergences that appeared in unrelated groups, they might be instead, part of a transformation series that involves taxa closely related to the early amniotes as some hypotheses have suggested.

scholarly journals The ontogenetic transformation of the mesosaurid tarsus: a contribution to the origin of the primitive amniotic astragalus

2016 ◽  
Author(s):  
Graciela Piñeiro ◽  
Pablo Núñez Demarco ◽  
Melitta D Meneghel
Keyword(s):  
The Other ◽  
Ossification Center ◽  
Advanced Stage ◽  
Late Permian ◽  
Early Permian ◽  
Stage Of Development ◽  
Tarsal Bones ◽  
Single Bone ◽  
Transformation Series

The hypotheses about the origin of the primitive amniotic tarsus are very speculative. Early studies argued that the origin of the astragalus, one of the largest proximal bones in the tarsus of basal amniotes, was produced by either the fusion of two, three, or even four of the original tarsal bones, the intermedium, the tibiale and the proximal centralia (c4 and c3), or that the intermedium alone transforms into the primitive astragalus. More recent studies have shown that the structure of the tarsus in Captorhinus supports the former hypothesis about a fusion of the intermedium, the tibiale, the proximal centrale (c4) and eventually c3, producing a purportedly multipartite structure of the amniotic astragalus, but the issue remained contentious. Very well preserved tarsi of the Early Permian aquatic amniote Mesosaurus tenuidens Gervais, 1864-1865, which represent the most complete ontogenetic succession known for a basal amniote (the other exceptional one is provided by the Late Permian diapsid Hovasaurus boulei Piveteau, 1926), suggest that there is more than one ossification center for the astragalus and that these fuse during late embryonic stages or maybe early after birth. A non-hatched Mesosaurus in an advanced stage of development shows that the tarsus is represented by a single bone, most probably the astragalus, which seems to be formed by the suturing of three bones, which we interpret as being the intermedium, the tibiale, which could have already integrated the c4 in an earlier stage of the development, and the c3. An amniote-like tarsal structure is observed in very basal Carboniferous and Permian tetrapods such as Proterogyrinus, Gephyrostegus, the diadectids Diadectes and Orobates, some microsaurs like Tuditanus and Pantylus, and possibly Westlothiana, taxa that were all considered as true amniotes in their original descriptions. Therefore, the structure of the amniotic tarsus, including the configuration of the proximal series formed by the astragalus and the calcaneum, typically a pair of enlarged bones, could have been established well before the first recognized amniote walked on Earth. Accordingly, the tarsus of these taxa does not constitute specialized convergences that appeared in unrelated groups, they might be instead, part of a transformation series that involves taxa closely related to the early amniotes as some hypotheses have suggested.

scholarly journals III. The menstruation and ovulation of macacus rhesus, with observations on the changes undergone by the discharged follicle.—Part II

1897 ◽  
Vol 188 ◽  
pp. 135-166 ◽  
Keyword(s):  
Menstrual Cycle ◽  
In Utero ◽  
The Other ◽  
Advanced Stage ◽  
Stage Of Development ◽  
Stage 1

The greater part of the material wherewith the work detailed in this paper was done, was obtained during my stay in Calcutta during the early part of 1891, and I am greatly indebted to the Committee of Management of the Calcutta Zoological Gardens, and especially to Professor D. D. Cunningham, F. R. S., both for assistance in getting the animals required and for facilities placed at my disposal for carrying on my work in that country. Two hundred female Macacus rhesus were gent to me from Muttra and thirty from Benares. A very large proportion of these either had embryos in an advanced stage of development in utero, or had recently borne young; of the remainder many had not yet reached the age of puberty, and when all doubtful cases were excluded, seventeen specimens alone remained which could be used for the purpose of investigating the phenomena of menstruation. Five of these were referable to Stage 1, the resting or intermenstrual stage, and the other twelve to various stages of the menstrual cycle.

The yields of wholesale cuts from carcasses of Aberdeen-Angus crosses fattened on grass and in yards

1959 ◽  
Vol 53 (1) ◽  
pp. 64-77 ◽  
Author(s):  
G. Harrington ◽  
R. W. Pomeroy
Keyword(s):  
The Other ◽  
Advanced Stage ◽  
Stage Of Development

1. Both sides of sixty-eight carcasses of Aberdeen-Angus cross steers and heifers were broken down into wholesale joints by the same butcher using a modification of the London and Home Counties style of cutting. Thirty-four of the cattle were fattened on grass in the summer of 1955 and the other thirty-four in yards during the following winter.2. Sides of steer carcasses averaged some 50–60 lb. heavier than those of heifers both in summer and winter, and the yard-fattened cattle gave sides averaging 10–20 lb. heavier than those from grassfattened cattle.3. The cuts along the underline of the animals (brisket and flanks) were increasing in weight at proportionally the greatest rate and the shin and hind-leg cuts at about half this rate, with those along the top of the back intermediate.4. At a side weight of 300 lb., steers were significantly lighter than heifers in the weight of kidney knob, cod fat, thin flank, forequarter flank, loin and rump, whereas they were significantly heavier than heifers in weight of leg, shin, topside, top rump and the neck cuts (clod and sticking). These differences suggested that at this weight of side, heifers were at a more advanced stage of development than steers.

The Application of UX Research in New Energy Vehicle Innovation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU
Keyword(s):  
Early Stage ◽  
Rapid Expansion ◽  
The Other ◽  
Innovative Product ◽  
Stage Of Development ◽  
New Energy ◽  
New Energy Vehicle ◽  
The One ◽  
New Energy Vehicles ◽  
Degree Of Innovation

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.

Morphometric Studies on The Tarsal Bones of Blue Bull (Boselaphus tragocamelus

2016 ◽  
Vol 12 (2) ◽  
Author(s):  
Sanjay Kumar Bharti ◽  
Ishwer Singh ◽  
Balwinder Singh Dhote ◽  
Om Prakash Choudhary ◽  
Meena Mrigesh
Keyword(s):  
Average Height ◽  
Internal Part ◽  
Tarsal Bones ◽  
Single Bone

A study was carried out on the tarsal bones of blue bull. The tarsus of blue bull consisted of five bones i.e., tibial tarsal (Astragalus), fibular tarsal (Oscalcis), fused central and fourth tarsal (Scaphocuboid), first tarsal (Cunciformparvum) and second and third tarsal fused (Cuseiform magnum).The average height and breadth of tibial tarsal was 6.81±0.01 cm and 3.84±0.01 cm, respectively. The fibular tarsal was the longest, elongated bone of the tarsus and flattened from side to side with an average height and breadth 12.00±0.01 cm and 3.72±0.01 cm, respectively. The central and the fourth tarsalswere fused together to form a large single bone. The average height and breadth for central and fourth fused tarsal was 2.54±0.01 cm and 5.11±0.01 cm, respectively. The first tarsal was a quadrilateral piece of bone placed at the postero-internal part of the tarsus. The length and maximum breadth of first tarsal was 2.14±0.01 cm and 3.32±0.01 cm, respectively. The second and third fused tarsal was a small plate of bone having length and breadth of second and third fused tarsal 1.68±0.01 cm and 3.34±0.01 cm, respectively.

scholarly journals Bilateral Sturge Weber Syndrome- a rare case report

2013 ◽  
Vol 5 (1) ◽  
pp. 129-132 ◽  
Author(s):  
P Singh ◽  
S Singh
Keyword(s):  
Case Report ◽  
Rare Case ◽  
Unusual Case ◽  
The Other ◽  
Advanced Stage ◽  
Weber Syndrome ◽  
Rare Case Report ◽  
The Face ◽  
Bilateral Condition ◽  
Sturge Weber Syndrome

Background: Sturge-Weber syndrome is a rare congenital neuro- oculo- cutaneous disorder. Objective: To report a very rare unusual case of bilateral manifestation of Sturge Weber syndrome. Case: We report an unusual case of a 17-year-old female with advanced stage of bilateral glaucoma associated with facial nevus extending to the other half of the face as well and bilateral intracranial calcification. Conclusion: Sturge -Weber syndrome can manifest as a bilateral condition. Nepal J Ophthalmol 2013; 5(9):129-132 DOI: http://dx.doi.org/10.3126/nepjoph.v5i1.7841

scholarly journals Note on a Leptocephalus Stage of the Conger

1920 ◽  
Vol 12 (2) ◽  
pp. 249-252 ◽  
Author(s):  
E. Ford
Keyword(s):  
The Body ◽  
Advanced Stage ◽  
Young Fish ◽  
Dorsal Fin ◽  
Close Resemblance ◽  
Stage Of Development ◽  
Fin Rays ◽  
Glass Aquarium

On September 17th, 1919, a specimen of Leptocephalus Congri vulgaris (L. Morrisii) was captured in “bottom” haul No. 69 of the young fish trawl in locality Eddystone bearing S. by W. (magnetic) 1½ miles, over a depth of 31 fathoms. It was alive and active when taken, measuring between 115 and 120 mm. in length, and has been kept alive up to the present date in a glass aquarium under circulation. It was at a fairly advanced stage of development, intermediate between those exhibited in Figs. 2 and 3, Pl. I of Schmidt (1), the dorsal fin commencing slightly farther back than in Fig. 3, and the median row of pigment spots along either side of the body not extending forward beyond about 1 cm. in front of the commencement of the dorsal fin. There is a close resemblance also to the specimen figured by Fulton (2), with the exception that, as just pointed out, the median row of pigment along the body on either side does not reach forward quite to the head, and in addition the pigment spots at the base of the dorsal fin rays are only two or three in number, situated at the extreme posterior end of the fin.Since the date of capture, observations 'have been made periodically and certain measurements taken as accurately as possible, but on account of the movements of the fish the latter could only be obtained approximately.

Sign in / Sign up

Export Citation Format

Share Document