A state is not a point, and in Arizona finding a point with anything in it took some doing: Phoenix returns nothing at all in this window, and so does the state's own geographic centre. Holbrook returns 584. Of those, 581 lived on land and 3 did not — and the 3 sit at 100 million years ago, an age at which most other places on this site are under water. This is the page where the answer to the question in its own title is, mostly, no.
Five ages in the past of this place, each one a window rather than a day. Each says which witness spoke — and where our evidence cannot answer yet, it says that too.
“Ma” means millions of years ago. The dashed mark means our sources have nothing for that age — which is a finding, not a fault.
Three fossils out of 584
This site is called Triassic Water and most of its location pages end up talking about the sea. This one does not. 581 of the 584 fossils recorded around Holbrook are animals or plants the database records as living out of the water.
The exceptions — 100 million years ago
Mecaster batnensis · about 17.3 km away · 100.5–93.9 million years old
Pycnodonte · about 17.3 km away · 100.5–93.9 million years old
Cunningtoniceras arizonense · about 60.8 km away · 100.5–93.9 million years old
Three sea creatures, at 100 million years ago. That is the age at which nearly every other place on this site has its richest marine evidence — and here it produces three.
It is tempting to build something out of that. This page does not: three occurrences is three occurrences, and whether they mean the sea reached here, or that three things were washed somewhere, or simply that somebody dug in one spot and not another, is not something our sources answer. They are listed for the plain reason that they exist; leaving them out would tidy this page into a cleaner story than the record supports.
The wider point is about where the digging happened. Phoenix, the largest city in the state, returns nothing at all in this window. This box returns nearly six hundred. That gap is not a fact about ancient Arizona.
Travel back in time
Most of what this record holds sits in one row, and that row is about dry land. On a site whose other pages keep finding sea, it is worth reading slowly.
250
million years agojump to the evidence250 million years ago, the plate model puts this ground almost on the equator. Published models disagree by about 4.8° of latitude here — a few hundred kilometres — so it is one model's answer, not a photograph.
200
million years agojump to the evidence200 million years ago, the plate model puts this ground about 13° north of the equator. Published models agree more closely here, within about 2.3° of latitude, but it is still one model's answer rather than a photograph.
150
million years agojump to the evidence150 million years ago, the plate model puts this ground about 22° north of the equator. Published models disagree by about 4.1° of latitude here — a few hundred kilometres — so it is one model's answer, not a photograph.
100
million years agojump to the evidence100 million years ago, the plate model puts this ground about 35° north of the equator. Published models agree more closely here, within about 2.8° of latitude, but it is still one model's answer rather than a photograph.
66
million years agojump to the evidence66 million years ago, the plate model puts this ground about 39° north of the equator. Published models agree more closely here, within about 0.9° of latitude, but it is still one model's answer rather than a photograph.
What was the water doing?
Five ages, oldest first. Each one has two kinds of witness — the rock of the wider region, and the fossils dug up near the town — and they are kept apart on purpose, because they are answers to different questions.
Each age here is a marker on the timeline, not a single day. The evidence that belongs to it comes with an age range of its own that overlaps the marker — so it can tell you what this stretch of time was like, and never what was happening on one exact date.
One formation, both worlds
Around 250 million years ago
250 million years ago, the plate model puts this ground almost on the equator. Published models disagree by about 4.8° of latitude here — a few hundred kilometres — so it is one model's answer, not a photograph.
The rock of the region
Across the wider region, the rock from 250 million years ago carries both kinds of environment — parts of it laid down in the sea, parts of it on land. And it is one and the same rock formation, the Moenkopi Fm, carrying both. That is a statement about roughly 49,800 square kilometres of region, centred about 117 km from the town — not about the ground under one street.
The fossils dug up nearby
No fossil dug up near here has an age range that covers 250 million years ago, so there is no local evidence for this exact age.
Our evidence has no witness here
Around 200 million years ago
200 million years ago, the plate model puts this ground about 13° north of the equator. Published models agree more closely here, within about 2.3° of latitude, but it is still one model's answer rather than a photograph.
An open question
Neither of the evidence sources we use can answer this one: our regional rock record holds no unit for 200 million years ago at this point, and no fossil dug up nearby covers that age either. That is a real gap in the evidence, not a gap in the past — and saying so is more useful than guessing.
Our evidence has no witness here
Around 150 million years ago
150 million years ago, the plate model puts this ground about 22° north of the equator. Published models disagree by about 4.1° of latitude here — a few hundred kilometres — so it is one model's answer, not a photograph.
An open question
Neither of the evidence sources we use can answer this one: our regional rock record holds no unit for 150 million years ago at this point, and no fossil dug up nearby covers that age either. That is a real gap in the evidence, not a gap in the past — and saying so is more useful than guessing.
Only the fossils speak
Around 100 million years ago
100 million years ago, the plate model puts this ground about 35° north of the equator. Published models agree more closely here, within about 2.8° of latitude, but it is still one model's answer rather than a photograph.
The rock of the region
No rock layer from 100 million years ago survives in the regional record here, so the rock has nothing to say about this age.
The fossils dug up nearby
3 fossils dug up near Holbrook have an age range covering 100 million years ago: 3 from the sea, 0 from land. The closest of them was found about 17 km away — near the town, never under it.
Our evidence has no witness here
Around 66 million years ago
66 million years ago, the plate model puts this ground about 39° north of the equator. Published models agree more closely here, within about 0.9° of latitude, but it is still one model's answer rather than a photograph.
An open question
Neither of the evidence sources we use can answer this one: our regional rock record holds no unit for 66 million years ago at this point, and no fossil dug up nearby covers that age either. That is a real gap in the evidence, not a gap in the past — and saying so is more useful than guessing.
What was dug up nearby?
Everything below came out of the ground around Holbrook, never under it, so each row carries its distance. Scan the environment column and you will find three entries that are not like the others.
Around 100 million years ago
A Mecaster batnensis from 100 million years ago was dug up about 17 km from here, in the Mancos Shale, Coconino County.
A Pycnodonte from 100 million years ago was dug up about 17 km from here, in the Mancos Shale (lower shale).
A Cunningtoniceras arizonense from 100 million years ago was dug up about 61 km from here, in the Dakota Sandstone, Apache County.
Around 200 million years ago
A Leptosuchus from around this time (its own age range is 205.7–227.3 million years) was dug up about 18 km from here, in the Chinle (Petrified Forest), Navajo County.
A Selaginella from around this time (its own age range is 205.7–237 million years) was dug up about 18 km from here, in the Chinle (Monitor Butte).
A Dechellyia gormani from around this time (its own age range is 205.7–237 million years) was dug up about 18 km from here, in the Chinle (Monitor Butte).
Around 250 million years ago
A Dicynodontia from around this time (its own age range is 244.4–247 million years) was dug up about 0.8 km from here, in the Moenkopi (Holbrook), Navajo County.
A trace fossil called Therapsipus cumminsi — a name for a mark an animal left, not for the animal itself — from around this time (its own age range is 244.4–247 million years) was dug up about 0.8 km from here, in the Moenkopi (Holbrook), Navajo County.
A trace fossil called Therapsipus cumminsi — a name for a mark an animal left, not for the animal itself — from around this time (its own age range is 244.4–247 million years) was dug up about 0.8 km from here, in the Moenkopi (Holbrook), Navajo County.
We show these places to the nearest few kilometres rather than pinning them exactly. The scientists who recorded them know the spot far better than that — the full record is one click away in the Paleobiology Database, and it is free for anyone to read. We round them here because a map made for children is not a map for digging things up, not because anything is being hidden.
What changed?
The plate model gives this ground a position at every age and moves it north through the page. That is where a piece of the surface sat, and nothing more.
The rock at the surface today is younger than all of it. The geological map of this exact point returns Mesozoic sedimentary rocks (Mesozoic), Triassic sedimentary (Mesozoic), Holocene surficial deposits (Holocene).
Arizona's capital and its geographic centre both return nothing in this window. This page is a box around a town in the north-east and is not a description of the state.
Try it yourself
Land animals need fresh water as much as sea creatures need salt. A dry place is not a place without water; it is a place where the water is harder to find.
Good for testing a site's own bias. This one is about water and keeps finding seas — and here is a page where the honest answer is mostly no, printed at the same size as all the others.
If three fossils out of nearly six hundred point a different way, is that a discovery, a mistake, or just three fossils?
How sure are we?
Column facts describe an area of thousands to tens of thousands of km², centred tens of kilometres from the town coordinate. They are claims about a region, never about the rock beneath the town.
Fossil facts are a bounding-box sample around the town, each with its own distance from it; a fossil is never "here". The absence of fossils is not evidence of the absence of life — only of the absence of a recorded, published dig in this box.
Positions are model outputs, not observations. Independent plate models disagree by hundreds of kilometres at these ages, and that spread is the honest size of the uncertainty.
The land/sea question is answered only by the regional rock and the local fossils, separately, and never by the reconstruction — which says where this ground was and cannot say whether it was wet. There is deliberately no single field holding a one-word answer, because answering in one word would require merging a regional claim with a local one (CLAUDE.md rule 5). The nearby fossils are reported as a census of what has been found — which kinds are present, and how many of each — and never counted into a verdict: occurrence records are not statistically equivalent observations, so a plurality of them cannot establish an environment (science review, 2026-08-30).
Fossils are binned to their nearest slice age by age-range midpoint, with boundaries at the inter-slice midpoints 83, 125, 175 and 225 Ma. Those boundaries are an editorial choice, not a published stratigraphic scheme; a reviewer may prefer stage boundaries. Every occurrence keeps its own age range so the choice can be re-examined.
Sources
Macrostrat — the rock of the regionRead from version 2.3.9 of its data service on 2 September 2026.Peters, S.E. et al. Macrostrat: a platform for geological data integration and deep-time research. https://macrostrat.org, accessed on (date)Palaeogeography: Wright, N., Zahirovic, S., Müller, R. D., and Seton, M. Towards community-driven paleogeographic reconstructions: integrating open-access paleogeographic and paleobiology data with plate tectonics. Biogeosciences 10:1529-1541
The Paleobiology Database — the fossils dug up nearbyPBDB publishes no dataset version string; the data-service path (data1.2) and the datainfo access_time bound this claim.Fossil occurrence data from the Paleobiology Database (https://paleobiodb.org), released under CC0 1.0.Palaeo-coordinate cross-check (Paleobiology Database `pgm=gplates`): Wright et. al., 2013; Towards community-driven paleogeographic reconstructions.Palaeo-coordinate cross-check (Paleobiology Database `pgm=scotese`): Scotese, C.R., 2021. An Atlas of Paleogeographic Maps: The Seas Come In and the Seas Go Out, Annual Reviews of Earth and Planetary Sciences, v. 49, p. 669-718.Palaeo-coordinate cross-check (Paleobiology Database `pgm=seton`): Seton et. al., 2012; Global continental and ocean basin reconstructions since 200 Ma.
The EarthByte plate model — where this ground used to beMULLER2019 version 3.0, run with pyGPlates 1.0.0, licensed CC BY 4.0.GPlates: Müller, R. D., Cannon, J., Qin, X., Watson, R. J., Gurnis, M., Williams, S., Pfaffelmoser, T., Seton, M., Russell, S. H. J., Zahirovic S. (2018). GPlates: Building a virtual Earth through deep time. Geochemistry, Geophysics, Geosystems, 19, 2243-2261. https://doi.org/10.1029/2018GC007584Reconstructions computed with the GPlates Web Service (EarthByte Group, The University of Sydney).Plate model: Müller, R. D., Zahirovic, S., Williams, S. E., Cannon, J., Seton, M., Bower, D. J., Tetley, M. G., Heine, C., Le Breton, E., Liu, S., Russell, S. H. J., Yang, T., Leonard, J., and Gurnis, M. (2019), A global plate model including lithospheric deformation along major rifts and orogens since the Triassic. Tectonics, vol. 38, https://doi.org/10.1029/2018TC005462. Licensed CC BY 4.0.Plate model: Zahirovic, S., Eleish, A., Doss, S., Pall, J., Cannon, J., Pistone, M., Tetley, M. G., Young, A., & Fox, P. (2022). Subduction kinematics and carbonate platform interactions. Geoscience Data Journal, 9(2), p.371-383. Licensed CC BY 4.0.Coastline and static-polygon data by the EarthByte Group, licensed CC BY 3.0 Unported.
This record was assembled on from the datasets above. The ancient positions are reconstructions from a published plate model, not observations.
