Vertebrae-Based Body Length Estimation in Crocodylians and Its Implication for Sexual Maturity and the Maximum Sizes

Iijima, Masaya; Kubo, Tetsuo

doi:10.1093/iob/obaa042

Cited by 8 publications

(9 citation statements)

References 123 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The holotype (XM 12-1558) and a paratype (SM E1623) show closed neurocentral sutures in precaudal vertebrae, indicating sexual maturity [28,45,46], although their sexes are unknown. Body length (SVL and TL) estimates are 2.83 m SVL and 5.43 m TL for XM 12-1558 (figure 2 s ), 3.23 m SVL and 6.19 m TL for XM 12-1557, 2.88 m SVL and 5.57 m TL for SM E1623 and 3.09 m SVL and 5.97 m TL for SM S01812.…”

Section: Resultsmentioning

confidence: 99%

“…Snout-vent length (SVL) and total length (TL) of the holotype (XM 12-1558) and a paratype (SM E1623) of Hanyusuchus sinensis gen. et sp. nov. were estimated from the sum of the presacral centrum lengths and the sum of the cervical centrum lengths, respectively, using the equations in Iijima and Kubo [28]. Body lengths of the remaining paratypes without postcrania (XM 12-1557 and SM S01812) were estimated based on the skull-body length proportions in the holotype.…”

Section: Methods (A) Body Length Estimationmentioning

confidence: 99%

“…The holotype (XM 12-1558) and a paratype (SM E1623) show closed neurocentral sutures in precaudal vertebrae, indicating sexual maturity [28,45,46…”

Section: (Vi) Maturity and Body Sizementioning

confidence: 99%

See 2 more Smart Citations

An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction

et al. 2022

Self Cite

View full text Add to dashboard Cite

A solid phylogenetic framework is the basis of biological studies, yet higher level relationships are still unresolved in some major vertebrate lineages. One such group is Crocodylia, where the branching pattern of three major families (Alligatoridae, Crocodylidae and Gavialidae) has been disputed over decades due to the uncertain relationship of two slender-snouted lineages, gavialines and tomistomines. Here, we report a bizarre crocodylian from the Bronze Age of China, which shows a mosaic of gavialine and tomistomine features across the skeleton, rendering support to their sister taxon relationship as molecular works have consistently postulated. Gavialine characters of the new Chinese crocodylian include a novel configuration of the pterygoid bulla, a vocal structure known in mature male Indian gharials. Extinct gavialines have repeatedly evolved potentially male-only acoustic apparatus of various shapes, illuminating the deep history of sexual selection on acoustic signalling in a slender-snouted group of crocodylians. Lastly, a cutmark analysis combined with accelerator mass spectrometry (AMS) radiocarbon dating of bone remains demonstrated that two individuals from Shang and Zhou dynasties in Guangdong, China, suffered head injuries and decapitation. Archaeological evidence together with historical accounts suggests the human-induced extinction of this unique crocodylian only a few hundred years ago.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methods (A) Body Length Estimationmentioning

confidence: 99%

See 1 more Smart Citation

An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Body size. —Based on the size estimation of Toyotamaphimeia machikanensis (Iijima and Kubo, 2020), the body size of Toyotamaphimeia taiwanicus n. comb. is comparable (i.e., >6 m and up to 7 m long).…”

Section: Systematic Paleontologymentioning

confidence: 99%

“…8). All the fossil materials described here (except NSMT-P-9123) likely belong to physically and sexually mature individuals (>4 m and up to 7 m long; Iijima and Kubo, 2020; Iijima et al, 2022), eliminating the likelihood of ontogenetic differences (Iijima, 2017).…”

Section: Systematic Paleontologymentioning

confidence: 99%

Crocodylian princess in Taiwan: Revising the taxonomic status of Tomistoma taiwanicus from the Pleistocene of Taiwan and its paleobiogeographic implications

Cho

Tsai

2023

J. Paleontol.

View full text Add to dashboard Cite

Toyotamaphimeia is an extinct crocodylian lineage whose name is derived from a mythological Japanese princess. Here, we re-examine the type specimens of a long-forgotten species: Tomistoma taiwanicus from the Pleistocene of Tainan (Taiwan) and revise its taxonomic status to Toyotamaphimeia taiwanicus n. comb., leading to the first recognized species of Toyotamaphimeia outside Japan. Our phylogenetic analyses also support this taxonomic assignment and, more interestingly, further suggest an East Asian lineage. In addition, Toyotamaphimeia taiwanicus n. comb. represents a tropical species, resolving a long-standing puzzle of why Toyotamaphimeia only inhabited a much higher latitudinal area (Japan). Given the large body size of Toyotamaphimeia taiwanicus n. comb. (~7 m) and the fact that it is geologically older than Toyotamaphimeia machikanensis from Japan, we propose a novel evolutionary scenario: the genus Toyotamaphimeia originated in Taiwan and evolved to a large body size with gigantothermic physiology, which resulted in migration out of Taiwan and dispersal farther north to Japan. Our taxonomic identification shows the presence of an extinct endemic crocodylian species from the Pleistocene of Taiwan with large-scale paleogeographic implications. This study, with our recent progress in vertebrate paleontology in Taiwan, should provoke more in-depth paleontological research on the Pleistocene extinction.

show abstract

Evaluating growth in Macrospondylus bollensis (Crocodylomorpha, Teleosauroidea) in the Toarcian Posidonia Shale, Germany

Johnson,

Amson,

Maxwell

2023

Papers in Palaeontology

View full text Add to dashboard Cite

The study of how organisms grow is a fundamental aspect of palaeontology. Growth in teleosauroids is poorly understood and little studied, especially in an ontogenetic sense. We investigate growth rates of the most common and abundant teleosauroid, Macrospondylus bollensis, in which a large sample of multiple body sizes is available from the Posidonienschiefer Formation (Posidonia Shale) of southwestern Germany. We perform linear regression analyses on 62 specimens of Macrospondylus (16 juveniles, 7 subadults and 39 adults) using 21 cranial and postcranial measurements. Our results show that juvenile, subadult and adult individuals have near‐isometric or isometric growth throughout much of the body. Notably, we find that in Macrospondylus: (1) the femur grows at a faster rate than the skull and hindlimb zeugopodium; (2) the forelimb and hindlimb grow at the same rate; and (3) there is distinct ontogenetic signal in the growth of the orbit and supratemporal fenestra. We also find that limb scaling in Macrospondylus is somewhat comparable to that seen in the extant gavialids Gavialis gangeticus and Tomistoma schlegelii. Last, we examine evolutionary allometry in skull length relative to body size in Crocodylomorpha using femoral length as a proxy, which shows a near‐isometric trend. Non‐thalattosuchian crocodylomorphs (with the exception of one pholidosaurid and one dryosaurid taxon) are differentiated from thalattosuchians due to their shorter skulls, as previously suggested, but the scaling relationship with femur length remains unchanged.

show abstract

Vertebrae-Based Body Length Estimation in Crocodylians and Its Implication for Sexual Maturity and the Maximum Sizes

Cited by 8 publications

References 123 publications

An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction

An intermediate crocodylian linking two extant gharials from the Bronze Age of China and its human-induced extinction

Crocodylian princess in Taiwan: Revising the taxonomic status of Tomistoma taiwanicus from the Pleistocene of Taiwan and its paleobiogeographic implications

Evaluating growth in Macrospondylus bollensis (Crocodylomorpha, Teleosauroidea) in the Toarcian Posidonia Shale, Germany

Contact Info

Product

Resources

About