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Colalillo E, Solounias N. Preliminary ontogeny of the giraffe neck. Anat Rec (Hoboken) 2023; 306:2646-2651. [PMID: 36929340 DOI: 10.1002/ar.25193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/18/2023]
Abstract
The giraffe juvenile has different proportions of head to neck from the adult. The head just about doubles in size from the juvenile to adult, whereas the neck increases almost 4.5× (roughly four times) in length. The T1 posterior dorsal vertebral width of the newborn is clearly wider than in the adult where it is narrow. In the okapi, the dorsal vertebral width is narrow in both juvenile and adult. The giraffe neck changes in ontogeny anisometrically. In the okapi the changes are more isometric. The giraffe juvenile vertebrae are shorter and do not have fused the cranial epiphyseal plates. That facilitates anterior elongation-growth. The ventral tubercles are undeveloped. The juvenile T1 is wide caudally unlike the adult. This may be a similarity to a gelocid (Gelocidae) ancestor of the giraffe.
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Affiliation(s)
- Emily Colalillo
- NYITCOM Class of 2025 Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, New York, USA
- Department of Paleontology, American Museum of Natural History, New York, New York, USA
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Hou S, Shi Q, Benton MJ, Solounias N. Comment on "Sexual selection promotes giraffoid head-neck evolution and ecological adaptation". Science 2023; 379:eadd9559. [PMID: 36795824 DOI: 10.1126/science.add9559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Wang et al. (Research Articles, 3 June 2022, eabl8316) reported an early Miocene giraffoid that exhibited fierce head-butting behavior and concluded that sexual selection promoted head-neck evolution in giraffoids. However, we argue that this ruminant is not a giraffoid and thus that the hypothesis that sexual selection promoted giraffoid head-neck evolution is not sufficiently supported.
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Affiliation(s)
- Sukuan Hou
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Qinqin Shi
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China
| | | | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA.,Department of Paleontology, American Museum of Natural History, New York, NY, USA
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Smith S, Yohe LR, Solounias N. The bony cap and its distinction from the distal phalanx in humans, cats, and horses. PeerJ 2023; 11:e14352. [PMID: 36643632 PMCID: PMC9838202 DOI: 10.7717/peerj.14352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 10/17/2022] [Indexed: 01/12/2023] Open
Abstract
It has been recognized as early as the Victorian era that the apex of the distal phalanx has a distinct embryological development from the main shaft of the distal phalanx. Recent studies in regenerative medicine have placed an emphasis on the role of the apex of the distal phalanx in bone regrowth. Despite knowledge about the unique aspects of the distal phalanx, all phalanges are often treated as equivalent. Our morphological study reiterates and highlights the special anatomical and embryological properties of the apex of the distal phalanx, and names the apex "the bony cap" to distinguish it. We posit that the distal phalanx shaft is endochondral, while the bony cap is intramembranous and derived from the ectodermal wall. During development, the bony cap may be a separate structure that will fuse to the endochondral distal phalanx in the adult, as it ossifies well before the distal phalanges across taxa. Our study describes and revives the identity of the bony cap, and we identify it in three mammalian species: humans, cats, and horses (Homo sapiens, Felis catus domestica, and Equus caballus). During the embryonic period, we show the bony cap has a thimble-like shape that surrounds the proximal endochondral distal phalanx. The bony cap may thus play an inductive role in the differentiation of the corresponding nail, claw, or hoof (keratin structures) of the digit. When it is not present or develops erroneously, the corresponding keratin structures are affected, and regeneration is inhibited. By terming the bony cap, we hope to inspire more attention to its distinct identity and role in regeneration.
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Affiliation(s)
- Shannon Smith
- College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States
| | - Laurel R. Yohe
- Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, United States,Earth and Planetary Sciences, Yale University, New Haven, Connecticut, United States,North Carolina Research Center, Kannapolis, North Carolina, United States,Ecology and Evolution, State University of New York at Stony Brook, Stony Brook, New York, United States
| | - Nikos Solounias
- College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States,Department of Paleontology, American Museum of Natural History, New York, NY, United States
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Prothero DR, Domning D, Fordyce RE, Foss S, Janis C, Lucas S, Marriott KL, Metais G, Naish D, Padian K, Rössner G, Solounias N, Spaulding M, Stucky RM, Theodor J, Uhen M. On the Unnecessary and Misleading Taxon “Cetartiodactyla”. J MAMM EVOL 2021. [DOI: 10.1007/s10914-021-09572-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Buttar I, Solounias N. Specialized Position of the Horns, and Frontal and Parietal Bones in Bos taurus (Bovini, Artiodactyla), and Notes on the Evolution of Bos. ANN ZOOL FENN 2021. [DOI: 10.5735/086.058.0105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Irvind Buttar
- Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, NY 11568, USA
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Abstract
Abstract
Evolution has shaped the limbs of hoofed animals in specific ways. In artiodactyls, it is the common assumption that the metatarsal is composed of the fusion of digits III and IV, whereas the other three digits have been lost or are highly reduced. However, evidence from the fossil record and internal morphology of the metatarsal challenges these assumptions. Furthermore, only a few taxonomic groups have been analysed. In giraffes, we discovered that all five digits are present in the adult metatarsal and are highly fused and modified rather than lost. We examined high-resolution micro-computed tomography scans of the metatarsals of two mid and late Miocene giraffid fossils and the extant giraffe and okapi. In all the Giraffidae analysed, we found a combination of four morphologies: (1) four articular facets; (2) four or, in most cases, five separate medullary cavities internally; (3) a clear, small digit I; and (4) in the two fossil taxa of unknown genus, the presence of external elongated grooves where the fusions of digits II and V have taken place. Giraffa and Okapia, the extant Giraffidae, show a difference from all the extinct taxa in having more flattened digits tightly packed together, suggesting convergent highly fused digits despite divergent ecologies and locomotion. These discoveries provide evidence that enhances our understanding of how bones fuse and call into question current hypotheses of digit loss.
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Affiliation(s)
- Laurel R Yohe
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA
| | - Nikos Solounias
- Department of Paleontology, American Museum of Natural History, New York, NY, USA
- Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, NY, USA
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Abdel-Karim S, Monkash N, Dao B, Solounias N. The General Relationships of Giraffidae. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.04249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hou S, Cydylo M, Danowitz M, Solounias N. Comparisons of Schansitherium tafeli with Samotherium boissieri (Giraffidae, Mammalia) from the Late Miocene of Gansu Province, China. PLoS One 2019; 14:e0211797. [PMID: 30753231 PMCID: PMC6376930 DOI: 10.1371/journal.pone.0211797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 01/21/2019] [Indexed: 12/02/2022] Open
Abstract
We are describing and figuring for the first time skulls of
Schansitherium tafeli, which are abundant in the Gansu area
of China from the Late Miocene. They were animals about the size of
Samotherium with shorter necks that had two pairs of
ossicones that merge at the base, which is unlike Samotherium.
The anterior ossicones consist of anterior lineations, which may represent
growth lines. They were likely mixed feeders similar to
Samotherium. Schansitherium is tentatively
placed in a very close position to Samotherium.
Samotherium and Schansitherium represent a
pair of morphologically very similar species that likely coexisted similarly to
pairs of modern species, where the main difference is in the ossicones. Pairs of
ruminants in Africa, for example, exist today that differ mostly in their horn
shape but otherwise are similar in size, shape, and diet. The absence of
Schansitherium from Europe is interesting, however, as
Samotherium is found in both locations. While is it
challenging to interpret neck length and ossicone shape in terms of function in
combat, we offer our hypothesis as to how the two species differed in their
fighting techniques.
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Affiliation(s)
- Sukuan Hou
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese
Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology,
Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing,
China
- College of Earth and Planetary Sciences, University of Chinese Academy of
Sciences, Beijing, China
- * E-mail:
| | - Michael Cydylo
- Department of Anatomy, New York Institute of Technology College of
Osteopathic Medicine, Old Westbury, NY, United States of
America
| | - Melinda Danowitz
- Department of Pediatrics, Alfred I. duPont Hospital for Children,
Wilmington, DE, United States of America
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of
Osteopathic Medicine, Old Westbury, NY, United States of
America
- Department of Paleontology, American Museum of Natural History, New York,
NY, United States of America
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Solounias N, Danowitz M, Stachtiaris E, Khurana A, Araim M, Sayegh M, Natale J. The evolution and anatomy of the horse manus with an emphasis on digit reduction. R Soc Open Sci 2018; 5:171782. [PMID: 29410871 PMCID: PMC5792948 DOI: 10.1098/rsos.171782] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/15/2017] [Indexed: 06/08/2023]
Abstract
We revisit digit reduction in the horse and propose that all five digits are partially present in the modern adult forelimb. Osteological descriptions of selected tetradactyl, tridactyl and monodactyl equids demonstrate the evolution of the forelimb. Histological, osteological and palaeontological evidence suggest that the Equus distal forelimb is more complex than traditionally conceived. The current understanding is that the horse distal forelimb consists of one complete digit (III) and two reduced splint metacarpals (II and IV). Metacarpals II and IV each exhibit a ventral ridge, which we suggest represents the undifferentiated digits I and V. These ridges are present in the tridactyl Mesohippus, but are absent in the tetradactyl Hyracotherium. The carpal articulations of the five metacarpals match those of pentadactyl taxa. Distally, the frog, a V-shaped structure on the ventral hoof represents digits II and IV, and the wings and hoof cartilages of the distal phalanx are digits I and V. We relate this revised interpretation of the Equus forelimb to Laetoli footprints, and suggest the Hipparion side impressions are created from the hooves of I and V, rather than from II and IV. We show shades of pentadactyly within the Equus manus.
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Affiliation(s)
- Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
- Department of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
| | - Melinda Danowitz
- Department of Pediatrics, Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE 19803, USA
| | - Elizabeth Stachtiaris
- Department of Emergency Medicine, Brookdale University Hospital and Medical Center, 1 Brookdale Plaza, Brooklyn, NY 11212, USA
| | - Abhilasha Khurana
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Marwan Araim
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Marc Sayegh
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Jessica Natale
- Department of Internal Medicine, Saint Michael's Medical Center, 111 Central Avenue, Newark, NJ 07102, USA
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Camarata T, Howard A, Elsey RM, Raza S, O’Connor A, Beatty B, Conrad J, Solounias N, Chow P, Mukta S, Vasilyev A. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney. PLoS One 2016; 11:e0153422. [PMID: 27144443 PMCID: PMC4856328 DOI: 10.1371/journal.pone.0153422] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 03/29/2016] [Indexed: 11/19/2022] Open
Abstract
New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population.
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Affiliation(s)
- Troy Camarata
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Alexis Howard
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Ruth M. Elsey
- Louisiana Department of Wildlife and Fisheries, Grand Chenier, Louisiana, United States of America
| | - Sarah Raza
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Alice O’Connor
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Brian Beatty
- Department of Anatomy, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Jack Conrad
- Department of Anatomy, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Nikos Solounias
- Department of Anatomy, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Priscilla Chow
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Saima Mukta
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
| | - Aleksandr Vasilyev
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, Old Westbury, New York, United States of America
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Abstract
The artiodactyl astragalus has been modified to exhibit two trochleae, creating a double pullied structure allowing for significant dorso-plantar motion, and limited mediolateral motion. The astragalus structure is partly influenced by environmental substrates, and correspondingly, morphometric studies can yield paleohabitat information. The present study establishes terminology and describes detailed morphological features on giraffid astragali. Each giraffid astragalus exhibits a unique combination of anatomical characteristics. The giraffid astragalar morphologies reinforce previously established phylogenetic relationships. We find that the enlargement of the navicular head is a feature shared by all giraffids, and that the primitive giraffids possess exceptionally tall astragalar heads in relation to the total astragalar height. The sivatheres and the okapi share a reduced notch on the lateral edge of the astragalus. We find that Samotherium is more primitive in astragalar morphologies than Palaeotragus, which is reinforced by tooth characteristics and ossicone position. Diagnostic anatomical characters on the astragalus allow for giraffid species identifications and a better understanding of Giraffidae.
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Affiliation(s)
- Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, United States of America
- Department of Paleontology, American Museum of Natural History, Central Park West at 79 Street, New York, NY, United States of America
- * E-mail:
| | - Melinda Danowitz
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, United States of America
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Danowitz M, Domalski R, Solounias N. The cervical anatomy of Samotherium, an intermediate-necked giraffid. R Soc Open Sci 2015; 2:150521. [PMID: 26716010 PMCID: PMC4680625 DOI: 10.1098/rsos.150521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/27/2015] [Indexed: 06/05/2023]
Abstract
Giraffidae are represented by many extinct species. The only two extant taxa possess diametrically contrasting cervical morphology, as the okapi is short-necked and the giraffe is exceptionally long-necked. Samotherium major, known from the Late Miocene of Samos in Greece and other Eurasian localities, is a key extinct giraffid; it possesses cervical vertebrae that are intermediate in the evolutionary elongation of the neck. We describe detailed anatomical features of the cervicals of S. major, and compare these characteristics with the vertebrae of the two extant giraffid taxa. Based on qualitative morphological characters and a quantitative analysis of cervical dimensions, we find that the S. major neck is intermediate between that of the okapi and the giraffe. Specifically, the more cranial (C2-C3) vertebrae of S. major represent a mosaic of features shared either with the giraffe or with the okapi. The more caudal (C5-C7) S. major vertebrae, however, appear transitional between the two extant taxa, and hence are more unique. Notably, the C6 of S. major exhibits a partially excavated ventral lamina that is strong cranially but completely absent on the caudal half of the ventral vertebral body, features between those seen in the giraffe and the okapi. Comprehensive anatomical descriptions and measurements of the almost-complete cervical column reveal that S. major is a truly intermediate-necked giraffid. Reconstructions of the neck display our findings.
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Affiliation(s)
- Melinda Danowitz
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Rebecca Domalski
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
- Department of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
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14
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Danowitz M, Vasilyev A, Kortlandt V, Solounias N. Fossil evidence and stages of elongation of the Giraffa camelopardalis neck. R Soc Open Sci 2015; 2:150393. [PMID: 26587249 PMCID: PMC4632521 DOI: 10.1098/rsos.150393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
Several evolutionary theories have been proposed to explain the adaptation of the long giraffe neck; however, few studies examine the fossil cervical vertebrae. We incorporate extinct giraffids, and the okapi and giraffe cervical vertebral specimens in a comprehensive analysis of the anatomy and elongation of the neck. We establish and evaluate 20 character states that relate to general, cranial and caudal vertebral lengthening, and calculate a length-to-width ratio to measure the relative slenderness of the vertebrae. Our sample includes cervical vertebrae (n=71) of 11 taxa representing all seven subfamilies. We also perform a computational comparison of the C3 of Samotherium and Giraffa camelopardalis, which demonstrates that cervical elongation occurs disproportionately along the cranial-caudal vertebral axis. Using the morphological characters and calculated ratios, we propose stages in cervical lengthening, which are supported by the mathematical transformations using fossil and extant specimens. We find that cervical elongation is anisometric and unexpectedly precedes Giraffidae. Within the family, cranial vertebral elongation is the first lengthening stage observed followed by caudal vertebral elongation, which accounts for the extremely long neck of the giraffe.
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Affiliation(s)
- Melinda Danowitz
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
| | - Aleksandr Vasilyev
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
| | - Victoria Kortlandt
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
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Backus TC, Solounias N, Mihlbachler MC. The Brachial Plexus of the Sumatran Rhino (Dicerorhinus sumatrensis) and Application of Brachial Plexus Anatomy Toward Mammal Phylogeny. J MAMM EVOL 2015. [DOI: 10.1007/s10914-015-9297-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hager S, Backus T, Futterman B, Solounias N, Mihlbachler MC. A Subscapular Approach to the Dissection of the Human Brachial Plexus. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.960.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shaun Hager
- Anatomy; New York Institute of Technology College of Osteopathic Medicine; Old Westbury NY
| | - Timothy Backus
- Anatomy; New York Institute of Technology College of Osteopathic Medicine; Old Westbury NY
| | - Bennett Futterman
- Anatomy; New York Institute of Technology College of Osteopathic Medicine; Old Westbury NY
| | - Nikos Solounias
- Anatomy; New York Institute of Technology College of Osteopathic Medicine; Old Westbury NY
| | - Matthew C Mihlbachler
- Anatomy; New York Institute of Technology College of Osteopathic Medicine; Old Westbury NY
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Rivals F, Solounias N. Differences in Tooth Microwear of Populations of Caribou (Rangifer tarandus, Ruminantia, Mammalia) and Implications to Ecology, Migration, Glaciations and Dental Evolution. J MAMM EVOL 2007. [DOI: 10.1007/s10914-007-9044-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Godfrey LR, Semprebon GM, Jungers WL, Sutherland MR, Simons EL, Solounias N. Dental use wear in extinct lemurs: evidence of diet and niche differentiation. J Hum Evol 2004; 47:145-69. [PMID: 15337413 DOI: 10.1016/j.jhevol.2004.06.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2002] [Accepted: 06/08/2004] [Indexed: 11/18/2022]
Abstract
A new technique for molar use-wear analysis is applied to samples of all 16 species of extinct lemurs with known dentitions, as well as to a large comparative sample of extant primates. This technique, which relies on the light refractive properties of wear pits and scratches as seen under a standard stereoscopic microscope, has shown itself to be effective in distinguishing the diets of ungulates and extant primates. We draw dietary inferences for each of the 16 extinct lemur species in our database. There is a strong phylogenetic signal, with the Palaeopropithecidae showing use-wear signatures similar to those of the Indriidae; extinct lemurids (Pachylemur spp.) showing striking similarities to extant lemurids (except Hapalemur spp.); and Megaladapis showing similarities to Lepilemur spp. Only the Archaeolemuridae have dietary signatures unlike those of any extant lemurs, with the partial exception of Daubentonia. We conclude that the Archaeolemuridae were hard-object feeders; the Palaeopropithecidae were seed predators, consuming a mixed diet of foliage and fruit to varying degrees; Pachylemur was a fruit-dominated mixed feeder, but not a seed predator; and all Megaladapis were leaf browsers. There is no molar use wear evidence that any of the extinct lemurs relied on terrestrial foods (C4 grasses, tubers, rhizomes). This has possible implications for the role of the disappearance of wooded habitats in the extinction of lemurs.
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Affiliation(s)
- Laurie R Godfrey
- Department of Anthropology, University of Massachusetts, 240 Hicks Way, Amherst, MA 01003, USA.
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Semprebon GM, Godfrey LR, Solounias N, Sutherland MR, Jungers WL. Can low-magnification stereomicroscopy reveal diet? J Hum Evol 2004; 47:115-44. [PMID: 15337412 DOI: 10.1016/j.jhevol.2004.06.004] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2003] [Accepted: 06/08/2004] [Indexed: 11/24/2022]
Abstract
A new method of scoring dental microscopic use wear, initially developed for and applied to extant and extinct ungulates, is here applied to primates, and the efficacy of the method as a tool for diagnosing diet in both ungulates and primates is established. The method employs standard refractive light microscopy instead of scanning electron microscopy (SEM), and all use-wear features are counted or scored under low magnification (35 x). We use measurement systems analysis (variance components analysis of sources of measurement error) to evaluate the consistency and reproducibility of measurements using this method. The method is shown to have low intra- and inter-observer measurement error, and to effectively distinguish among graminivores, folivores, and frugivores. It can also be used to identify seed predators and to diagnose hard-object feeding. The method is also shown to be robust to the selection of measurement site; it works equally well when applied to upper or to lower molars. Finally, we use analysis of variance to examine the consistency of the signals across mammalian orders, and discriminant function analysis to develop dietary diagnostic tools for a set of "classified" primates with known diets. We test the success of these tools not merely by examining their a posteriori classification "success," but by using them to construct predicted dietary profiles for a sample of unclassified extant primate species, again with known diets.
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Affiliation(s)
- Gina M Semprebon
- Department of Biology, Bay Path College, Longmeadow, MA 01106, USA.
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Zucconi WB, Guelfguat M, Solounias N. Approach to the educational opportunities provided by variant anatomy, illustrated by discussion of a duplicated inferior vena cava. Clin Anat 2002; 15:165-8. [PMID: 11877799 DOI: 10.1002/ca.1115] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Variant anatomy recognized during routine cadaveric dissection in the first year of medical school offers great learning potential by allowing students to gain enhanced understanding of an array of important subjects. It provides a framework for reviewing common morphology and embryogenesis of the structure in question, and through the help of appropriate faculty, yields insight into the potential medical, radiologic, and surgical implications. The frequency of clinically important anatomic variation is high enough to allow the gross anatomy laboratory to serve as an excellent teaching platform in this regard. Through anatomy, the student is introduced to the concept of patient individuality, and to the individualization of medical and surgical therapies. Recently, one of the variations encountered in our lab was a duplicated inferior vena cava. We describe our approach to such findings through a systematic discussion of the anatomy and embryology, as well as the radiologic and clinical correlates.
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Affiliation(s)
- William B Zucconi
- Department of Gross Anatomy, New York College of Osteopathic Medicine, Old Westbury, New York, USA.
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Abstract
A median accessory digastric muscle was revealed during a dissection of the submental region. The muscle was located between the anterior bellies of the digastrics, external to the mylohyoid and deep to the platysma. It appeared as a flat quadrilateral sheet. Its base arose from the front of the body of the hyoid bone near its upper border. Lower portion of the fibers, at the right base of the muscle, initially traveled perpendicular to the lower fibers of the right mylohyoid. The rest of the muscle had a median course, with the cranial end inserting into the mandible between the digastric fossae. The muscle elevated the hyoid bone and depressed the mandible when appropriate stress was applied. No other morphologic abnormalities were found in this region. Aberrant anterior bellies of the digastric muscles are uncommon and occur bilaterally or unilaterally. This observation of a median accessory digastric muscle has not previously been reported. Knowledge of this variant will help to avoid confusion with pathological conditions of the floor of the mouth and the submental region. It is relevant both for the interpretation of radiological images and during surgical procedures such as dissection of the anterior belly of the digastric for a malignant disease and graft positioning.
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Affiliation(s)
- M Guelfguat
- Department of Gross Anatomy, New York College of Osteopathic Medicine, Old Westbury, New York, USA.
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Abstract
Six sympatric species of 5-million-year-old (late Hemphillian) horses from Florida existed during a time of major global change and extinction in terrestrial ecosystems. Traditionally, these horses were interpreted to have fed on abrasive grasses because of their high-crowned teeth. However, carbon isotopic and tooth microwear data indicate that these horses were not all C4 grazers but also included mixed feeders and C3 browsers. The late Hemphillian Florida sister species of the modern genus Equus was principally a browser, unlike the grazing diet of modern equids. Late Hemphillian horse extinctions in Florida involved two grazing and one browsing species.
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Affiliation(s)
- BJ MacFadden
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA. Department of Anatomy, New York College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA. Department of Geology
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Cerling TE, Harris JM, Ambrose SH, Leakey MG, Solounias N. Dietary and environmental reconstruction with stable isotope analyses of herbivore tooth enamel from the Miocene locality of Fort Ternan, Kenya. J Hum Evol 1997; 33:635-50. [PMID: 9467773 DOI: 10.1006/jhev.1997.0151] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tooth enamel of nine Middle Miocene mammalian herbivores from Fort Ternan, Kenya, was analyzed for delta 13C and delta 18O. The delta 18O values of the tooth enamel compared with pedogenic and diagenetic carbonate confirm the use of stable isotope analysis of fossil tooth enamel as a paleoenvironmental indicator. Furthermore, the delta 18O of tooth enamel indicates differences in water sources between some of the mammals. The delta 13C values of tooth enamel ranged from -8.6(-)-13.0/1000 which is compatible with a pure C3 diet, though the possibility of a small C4 fraction in the diet of a few of the specimens sampled is not precluded. The carbon isotopic data do not support environmental reconstructions of a Serengeti-typed wooded grassland with a significant proportion of C4 grasses. This study does not preclude the presence of C3 grasses at Fort Ternan; it is possible that C3 grasses could have had a wider geographic range if atmospheric CO2 levels were higher than the present values.
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Affiliation(s)
- T E Cerling
- Department of Geology and Geophysics, University of Utah, Salt Lake City 84103, USA
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