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A gravid lizard from the Cretaceous of China and the early history of squamate viviparity

Overview of attention for article published in Naturwissenschaften, July 2011
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About this Attention Score

  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (94th percentile)
  • Good Attention Score compared to outputs of the same age and source (78th percentile)

Mentioned by

1 blog
4 tweeters
4 Wikipedia pages
2 Google+ users


22 Dimensions

Readers on

51 Mendeley
A gravid lizard from the Cretaceous of China and the early history of squamate viviparity
Published in
Naturwissenschaften, July 2011
DOI 10.1007/s00114-011-0820-1
Pubmed ID

Yuan Wang, Susan E. Evans


Although viviparity is most often associated with mammals, roughly one fifth of extant squamate reptiles give birth to live young. Phylogenetic analyses indicate that the trait evolved more than 100 times within Squamata, a frequency greater than that of all other vertebrate clades combined. However, there is debate as to the antiquity of the trait and, until now, the only direct fossil evidence of squamate viviparity was in Late Cretaceous mosasauroids, specialised marine lizards without modern equivalents. Here, we document viviparity in a specimen of a more generalised lizard, Yabeinosaurus, from the Early Cretaceous of China. The gravid female contains more than 15 young at a level of skeletal development corresponding to that of late embryos of living viviparous lizards. This specimen documents the first occurrence of viviparity in a fossil reptile that was largely terrestrial in life, and extends the temporal distribution of the trait in squamates by at least 30 Ma. As Yabeinosaurus occupies a relatively basal position within crown-group squamates, it suggests that the anatomical and physiological preconditions for viviparity arose early within Squamata.

Twitter Demographics

The data shown below were collected from the profiles of 4 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 51 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Spain 2 4%
Switzerland 1 2%
Germany 1 2%
United Kingdom 1 2%
Italy 1 2%
Unknown 45 88%

Demographic breakdown

Readers by professional status Count As %
Researcher 13 25%
Student > Ph. D. Student 9 18%
Student > Bachelor 8 16%
Professor 7 14%
Student > Master 5 10%
Other 9 18%
Readers by discipline Count As %
Agricultural and Biological Sciences 26 51%
Earth and Planetary Sciences 16 31%
Environmental Science 3 6%
Biochemistry, Genetics and Molecular Biology 3 6%
Veterinary Science and Veterinary Medicine 1 2%
Other 2 4%

Attention Score in Context

This research output has an Altmetric Attention Score of 19. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 23 February 2014.
All research outputs
of 10,467,610 outputs
Outputs from Naturwissenschaften
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Outputs of similar age
of 81,340 outputs
Outputs of similar age from Naturwissenschaften
of 14 outputs
Altmetric has tracked 10,467,610 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 94th percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 1,284 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 12.1. This one has done well, scoring higher than 89% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 81,340 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 94% of its contemporaries.
We're also able to compare this research output to 14 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 78% of its contemporaries.