Science February 2013 PMID 23393258

The placental mammal ancestor and the post-K-Pg radiation of placentals.

Maureen A O'Leary, Jonathan I Bloch, John J Flynn, Timothy J Gaudin, Andres Giallombardo, Norberto P Giannini, Suzann L Goldberg, Brian P Kraatz, Zhe-Xi Luo, Jin Meng, Xijun Ni, Michael J Novacek, Fernando A Perini, Zachary S Randall, Guillermo W Rougier

Mentions

33
Peak: 9 in Feb 2013
across 4 sources since Feb 2013

Extended reach

22,410
potential audience

Total likes

183

Video views

3,114

Mentions per month

Feb 2013 – Nov 2025

Where it's discussed

  • News19 articles
  • X / Twitter9 posts
  • Blogs3 articles
  • YouTube2 videos

AI synopsis

What people are saying

Overall, posts express strong agreement and high interest, often highlighting the study's challenge to previous molecular hypotheses, such as references to fossils versus molecular clocks. The tone varies from academic engagement to enthusiasm, for example, one post calls the research a 'valuable contribution' while others discuss the implications for understanding the origin of placental mammals.

AgreementStrong agreement

Most posts support the findings and acknowledge the significance of the research, with some emphasizing mounting evidence and scientific debate.

InterestHigh interest

Discussions focus intensely on the implications of the study, showing high curiosity and engagement with the topic of mammal evolution.

EngagementModerate engagement

Many users reference specific methods, evidence, or broader debates, indicating active participation, though some posts are more surface-level or react with shared enthusiasm.

ImpactHigh impact

Discussants seem to recognize this research as a meaningful advancement in understanding mammalian evolution, with potential to influence future studies and debates.

Abstract in brief

  • The study used 4541 phenomic characters and molecular data from 86 species to build a phylogenetic tree, indicating that placental mammals originated after the Cretaceous-Paleogene (KPg) boundary.
  • The results challenge previous molecular findings by highlighting phenomic evidence that places Sundatheria (Dermoptera and Scandentia) as closest to Primates and confirms a close relationship between elephants (Proboscidea) and sea cows (Sirenia).
  • The tree suggests that the earliest placental mammals split into Xenarthra (armadillos, sloths) and Epitheria, with extinct New World species being some of the oldest Afrotheria members.]

Top posts

Most liked on X and Bluesky
Borrell Lab
@BorrellLab · X

@Mad_Lancaster @denisjabaudon @WiringTheBrain There is mounting evidence supporting this notion https://t.co/C85vWcmYfF https://t.co/6SiYJLJ97X

Jan 13, 2022 · 3 likes · 2,481 followers View post →
3D Anatomy Studios
@3DAnatomyStudio · X

Human #CTScan from the Visible Human Project: https://t.co/Q4RTOC8qg6. Our cat #CTScans available for free download at: https://t.co/YNoVzAgi7m. Estimate of 60+ million years since the most recent common ancestor of humans & cats from O'Leary et al. 2013: https://t.co/4TkdPMRccF.

May 26, 2021 · 3 likes · 1,449 followers View post →
Andrej Spiridonov
@AndrejSpiridon4 · X

@pastramimachine @TJNear This seems to be an artefact of the molecular clocks. The hypothesis of pre K-Pg radiation of modern placental mammals was falsified many times on the grounds of incongruence with the preservational constraints of the fossil record https://t.co/q8vC9kaxUz https://t.co/X5S1GMMgiJ

Mar 1, 2023 · 2 likes · 1,776 followers View post →
Rulon James Downard
@RJDownard · X

@Jesus_is_G_d @bubbacav85 @TertiusIII @TakeThatEpi @carlsmythe @tighe15 @StandBackUp2 @commonsensejan @michellmybell1 @rmbctious @ReviewResist @donholtmac @Cern_lXXl @Loriniowa @TedPerkins10 @LeannEAF @umfpt @Schmoop0521 @andyguy @MaryVMos1 @tklforgiven @geraldpayne25 @surgerysleeper @rorylane @rafearia @the_godparticle @RLBays @zythophiliac @feyeleanor @alan244g @phyzayo @funkydoolah @ScientiaPercept @2Cents69 @Mwforhr @omeagoz @Denbar64 @CollinOctantis @Kopernikus1966 @bobcat7000 @paulr140 @Pamiekp @TiSeven2 @CATGOD20 @delology @SteveTiger999 @amateurexegete Springer, Mark S., Robert W. Meredith, Emma C. Teeling, & William J. Murphy. 2013. “Technical Comment on ‘The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals’.” Science 341 (9 August): 613.

Jan 11, 2019 · 3,600 followers View post →
Rulon James Downard
@RJDownard · X

@Jesus_is_G_d @bubbacav85 @TertiusIII @TakeThatEpi @carlsmythe @tighe15 @StandBackUp2 @commonsensejan @michellmybell1 @rmbctious @ReviewResist @donholtmac @Cern_lXXl @Loriniowa @TedPerkins10 @LeannEAF @umfpt @Schmoop0521 @andyguy @MaryVMos1 @tklforgiven @geraldpayne25 @surgerysleeper @rorylane @rafearia @the_godparticle @RLBays @zythophiliac @feyeleanor @alan244g @phyzayo @funkydoolah @ScientiaPercept @2Cents69 @Mwforhr @omeagoz @Denbar64 @CollinOctantis @Kopernikus1966 @bobcat7000 @paulr140 @Pamiekp @TiSeven2 @CATGOD20 @delology @SteveTiger999 @amateurexegete O’Leary, Maureen et al. 2013. “The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals.” Science 339 (8 February): 662-667.

Jan 11, 2019 · 3,600 followers View post →
Dr F Tétard Matr 1620 @nacrespirale.cpesr.fr
@NACREspirale · X

The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals | Science https://t.co/nyuyjxREzR

Nov 28, 2023 · 2,964 followers View post →

All mentions

Alice de Sampaio Kalkuhl
@quantumlandbook · X

https://t.co/xN4ytDpe3L Love a good palaeo paper in the morning. I know the topic of ancestors for large groups is debated but I really liked the takes in this study. If anyone has good reads on a more recent state of the placental mammal origin debate, I'd love to read them.

Dec 4, 2023 · 1,128 followers View post →
Dr F Tétard Matr 1620 @nacrespirale.cpesr.fr
@NACREspirale · X

The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals | Science https://t.co/nyuyjxREzR

Nov 28, 2023 · 2,964 followers View post →
Andrej Spiridonov
@AndrejSpiridon4 · X

@pastramimachine @TJNear This seems to be an artefact of the molecular clocks. The hypothesis of pre K-Pg radiation of modern placental mammals was falsified many times on the grounds of incongruence with the preservational constraints of the fossil record https://t.co/q8vC9kaxUz https://t.co/X5S1GMMgiJ

Mar 1, 2023 · 2 likes · 1,776 followers View post →
Tom James
@TACJ · X

@robertsharp59 The paper https://t.co/47EfAbuHa7 The ancestor https://t.co/gHo5G09dej

Apr 18, 2022 · 1,478 followers View post →
Borrell Lab
@BorrellLab · X

@Mad_Lancaster @denisjabaudon @WiringTheBrain There is mounting evidence supporting this notion https://t.co/C85vWcmYfF https://t.co/6SiYJLJ97X

Jan 13, 2022 · 3 likes · 2,481 followers View post →
3D Anatomy Studios
@3DAnatomyStudio · X

Human #CTScan from the Visible Human Project: https://t.co/Q4RTOC8qg6. Our cat #CTScans available for free download at: https://t.co/YNoVzAgi7m. Estimate of 60+ million years since the most recent common ancestor of humans & cats from O'Leary et al. 2013: https://t.co/4TkdPMRccF.

May 26, 2021 · 3 likes · 1,449 followers View post →
苗子猫 @mys_721tx@genomic.social
@mys_721tx · X

https://t.co/WqKltyFesp // 早期胎盘动物每个象限有四个前磨牙 非胎盘真兽可能有五个... https://t.co/DocFl3Xlzt

Dec 12, 2020 · 601 followers View post →
Rulon James Downard
@RJDownard · X

@Jesus_is_G_d @bubbacav85 @TertiusIII @TakeThatEpi @carlsmythe @tighe15 @StandBackUp2 @commonsensejan @michellmybell1 @rmbctious @ReviewResist @donholtmac @Cern_lXXl @Loriniowa @TedPerkins10 @LeannEAF @umfpt @Schmoop0521 @andyguy @MaryVMos1 @tklforgiven @geraldpayne25 @surgerysleeper @rorylane @rafearia @the_godparticle @RLBays @zythophiliac @feyeleanor @alan244g @phyzayo @funkydoolah @ScientiaPercept @2Cents69 @Mwforhr @omeagoz @Denbar64 @CollinOctantis @Kopernikus1966 @bobcat7000 @paulr140 @Pamiekp @TiSeven2 @CATGOD20 @delology @SteveTiger999 @amateurexegete Springer, Mark S., Robert W. Meredith, Emma C. Teeling, & William J. Murphy. 2013. “Technical Comment on ‘The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals’.” Science 341 (9 August): 613.

Jan 11, 2019 · 3,600 followers View post →
Rulon James Downard
@RJDownard · X

@Jesus_is_G_d @bubbacav85 @TertiusIII @TakeThatEpi @carlsmythe @tighe15 @StandBackUp2 @commonsensejan @michellmybell1 @rmbctious @ReviewResist @donholtmac @Cern_lXXl @Loriniowa @TedPerkins10 @LeannEAF @umfpt @Schmoop0521 @andyguy @MaryVMos1 @tklforgiven @geraldpayne25 @surgerysleeper @rorylane @rafearia @the_godparticle @RLBays @zythophiliac @feyeleanor @alan244g @phyzayo @funkydoolah @ScientiaPercept @2Cents69 @Mwforhr @omeagoz @Denbar64 @CollinOctantis @Kopernikus1966 @bobcat7000 @paulr140 @Pamiekp @TiSeven2 @CATGOD20 @delology @SteveTiger999 @amateurexegete O’Leary, Maureen et al. 2013. “The Placental Mammal Ancestor and the Post-K-Pg Radiation of Placentals.” Science 339 (8 February): 662-667.

Jan 11, 2019 · 3,600 followers View post →
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