Nav: Home

Trilobite eggs in New York

February 23, 2017

Boulder, Colo., USA - Despite a plethora of exceptionally preserved trilobites, trilobite reproduction has remained a mystery. No previously described trilobite has had unambiguous eggs or genitalia preserved. This study by Thomas A. Hegna and colleagues reports the first occurrence of in situ preserved trilobite eggs from the Lorraine Group in upstate New York, USA.

Like other exceptionally preserved trilobites from the Lorraine Group, the complete exoskeletons are replaced with pyrite. The eggs are spherical to elliptical in shape and nearly 200 micrometers in size.

The location of the eggs is consistent with where modern female horseshoe crabs release their unfertilized eggs from the ovarian network within their head. Trilobites likely released their eggs and sperm through a genital pore of as-yet-unknown location (but probably near the posterior boundary of the head).

Because pyrite preferentially preserves the external features of fossils, there is probably a bias in the fossil record toward the preservation of arthropods that brood eggs externally. If the reproductive biology of these trilobites is representative of other trilobites, they likely spawned with external fertilization as well, which may be the ancestral mode of reproduction for early arthropods.


Pyritized in situ trilobite eggs from the Ordovician of New York (Lorraine Group): Implications for trilobite reproductive biology

Thomas A. Hegna, Markus J. Martin, and Simon A.F. Darroch


Local glaciation in West Greenland linked to North Atlantic Ocean circulation during the Holocene

Avriel D. Schweinsberg, Jason P. Briner, Gifford H. Miller, Ole Bennike, and Elizabeth K. Thomas

CO2 diffusion into pore spaces limits weathering rate of an experimental basalt landscape
Joost van Haren, Katerina Dontsova, Greg A. Barron-Gafford, Peter A. Troch, Jon Chorover, Stephen B. Delong, David D. Breshears, Travis E. Huxman, Jon D. Pelletier, Scott R. Saleska, Xubin Zeng, and Joaquin Ruiz

Bacterial sulfur disproportionation constrains timing of Neoproterozoic oxygenation
Marcus Kunzmann, Thi Hao Bui, Peter W. Crockford, Galen P. Halverson, Clint Scott, Timothy W. Lyons, and Boswell A. Wing

Crustal sequestration of magmatic sulfur dioxide
John Mavrogenes and Jon Blundy

Quantifying the rise of the Himalaya orogen and implications for the South Asian monsoon
Lin Ding, R.A. Spicer, Jian Yang, Qiang Xu, Fulong Cai, Shun Li, Qingzhou Lai, Houqi Wang, T.E.V. Spicer, Yahui Yue, A. Shukla, G. Srivastava, M. Ali Khan, S. Bera, and R. Mehrotra
Open Access

Fault-controlled dolomitization in a rift basin
Cathy Hollis, Eivind Bastesen, Adrian Boyce, Hilary Corlett, Robert Gawthorpe, Jesal Hirani, Atle Rotevatn, and Fiona Whitaker

Location, location, location: The variable lifespan of the Laramide orogeny
Peter Copeland, Claire A. Currie, Timothy F. Lawton, and Michael A. Murphy

Accelerating slip rates on the Puente Hills blind thrust fault system beneath metropolitan Los Angeles, California, USA
Kristian J. Bergen, John H. Shaw, Lorraine A. Leon, James F. Dolan, Thomas L. Pratt, Daniel J. Ponti, Eric Morrow, Wendy Barrera, Edward J. Rhodes, Madhav K. Murari, and Lewis A. Owen

Equable end Mesoproterozoic climate in the absence of high CO2
Richard P. Fiorella and Nathan D. Sheldon

Ultrafast magmatic buildup and diversification to produce continental crust during subduction
Mihai N. Ducea, George W. Bergantz, James L. Crowley, and Juan Otamendi

A rapid lake-shallowing event terminated preservation of the Miocene Clarkia Fossil Konservat-Lagersta¨tte (Idaho, USA)
Huanye Wang, Qin Leng, Weiguo Liu, and Hong Yang

What sets the size of current ripples?
Mathieu G.A. Lapotre, Michael P. Lamb, and Brandon McElroy

The Mw 8.3 Illapel earthquake (Chile): Preseismic and postseismic activity associated with hydrated slab structures
Piero Poli, Andrei Maksymowicz Jeria, and Sergio Ruiz

Late Quaternary glacial dynamics and sedimentation variability in the Bering Trough, Gulf of Alaska
Aleksandr Montelli, Sean P.S. Gulick, Lindsay L. Worthington, Alan Mix, Maureen Davies-Walczak, Sarah D. Zellers, and John M. Jaeger

A new Early Jurassic (ca. 183 Ma) fossil Lagersta¨tte from Ya Ha Tinda, Alberta, Canada
Rowan C. Martindale, Theodore R. Them, II, Benjamin C. Gill, Selva M. Marroquín, and Andrew H. Knoll
Open Access

Flexible and responsive growth strategy of the Ediacaran skeletal Cloudina from the Nama Group, Namibia
Rachel Wood, Andrew Curtis, Amelia Penny, Andrey Yu. Zhuravlev, Shona Curtis-Walcott, Secilie Iipinge, and Frederick Bowyer

The origin of contractional structures in extensional gneiss domes
P.F. Rey, L. Mondy, G. Duclaux, C. Teyssier, D.L. Whitney, M. Bocher, and C. Prigent

Combining Nd isotopes in monazite and Hf isotopes in zircon to understand complex open-system processes in granitic magmas
Christopher M. Fisher, John M. Hanchar, Calvin F. Miller, Stacy Phillips, Jeffrey D. Vervoort, and Martin J. Whitehouse

Coupling leeside grainfall to avalanche characteristics in aeolian dune dynamics
Joanna M. Nield, Giles F.S. Wiggs, Matthew C. Baddock, and Martin H.T. Hipondoka

Temperature and volume of global marine sediments
Douglas E. LaRowe, Ewa Burwicz, Sandra Arndt, Andrew W. Dale, and Jan P. Amend

Fossil forest reveals sunspot activity in the early Permian
Ludwig Luthardt and Ronny Ro¨ßler

Forecasting transitions in monogenetic eruptions using the geologic record
Gábor Kereszturi, Mark Bebbington, and Károly Németh
GEOLOGY articles are online Representatives of the media may obtain complimentary articles by contacting Kea Giles at the e-mail address above. Please discuss articles of interest with the authors before publishing stories on their work, and please make reference to GEOLOGY in articles published. Non-media requests for articles may be directed to GSA Sales and Service,

Geological Society of America

Related Reproduction Articles:

Proteins linked to HIV transmission could actually be beneficial for reproduction
Protein fragments found in semen, and previously only known for their ability to enhance HIV infection, also appear to play an important role in reproductive biology.
Human reproduction likely to be more efficient than previously thought
How difficult is it to conceive? According to a widely-held view, fewer than one in three embryos make it to term, but a new study from a researcher at the University of Cambridge suggests that human embryos are not as susceptible to dying in the first weeks after fertilization as often claimed.
Researchers find crucial clue to manipulating reproduction in plants
A team of researchers, led by a UC Riverside plant cell biologist, has for the first time identified a small RNA species and its target gene that together regulate female germline formation in plants -- crucial knowledge for manipulating plant reproduction in order to improve agriculture.
Why does so much of nature rely on sex for reproduction?
Why is sex so popular among plants and animals, and why isn't asexual reproduction, or cloning, a more common reproductive strategy?
The genetic basis for timing of reproduction in the Atlantic herring revealed
Animals need to breed at the time of year when their progeny have the best chance of survival.
More Reproduction News and Reproduction Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Teaching For Better Humans
More than test scores or good grades — what do kids need to prepare them for the future? This hour, guest host Manoush Zomorodi and TED speakers explore how to help children grow into better humans, in and out of the classroom. Guests include educators Olympia Della Flora and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#534 Bacteria are Coming for Your OJ
What makes breakfast, breakfast? Well, according to every movie and TV show we've ever seen, a big glass of orange juice is basically required. But our morning grapefruit might be in danger. Why? Citrus greening, a bacteria carried by a bug, has infected 90% of the citrus groves in Florida. It's coming for your OJ. We'll talk with University of Maryland plant virologist Anne Simon about ways to stop the citrus killer, and with science writer and journalist Maryn McKenna about why throwing antibiotics at the problem is probably not the solution. Related links: A Review of the Citrus Greening...